(E)-1-(4-(dimethylamino)but-2-enoyl)pyrrolidin-3-yl 4-((3-isopropyl-5-methylpyrazolo[1,5-a]pyrimidin-7-yl)amino)piperidine-1-carboxylate for inhibiting CDK7

ABSTRACT

The present invention provides novel CDK7 inhibitors and pharmaceutical compositions thereof: 
                         
or a pharmaceutically acceptable salt thereof.

The present invention relates to compounds useful for inhibiting cyclin-dependent kinase 7 (CDK7), pharmaceutical compositions, and methods for treating diseases related to CDK7 activity.

Cyclin-dependent kinases (CDKs) are a major class of kinases and are important in cancer cell proliferation and deregulated oncogenic transcription. CDK7 binds to cyclin H and MATI to form a trimeric cyclin-activating kinase (CAK) that performs its function by phosphorylating other CDKs involved in cell-cycle control. These complexes control specific transitions between two subsequent phases in the cell cycle. CDK7 is implicated in both temporal control of the cell cycle and transcriptional activity. CDK7 is implicated in the transcriptional initiation process by phosphorylation of Rbp1 subunit of RNA Polymerase II (RNAPII). Uncontrolled cell proliferation and deregulated transcription is a cancer hallmark. Targeting CDK7 selectively may offer an advantage by simultaneously inhibiting active transcription and cell-cycle progression. Therefore, CDK7 is a promising target for the treatment of cancer, in particular aggressive and hard-to-treat cancers.

Small molecule inhibitors against CDK7 have been reported in the literature (see, e.g., WO 2015/154022, WO 2016/142855, WO 2016/160617, WO 2016/193939, and WO 2017/044858). There remains a need to provide CDK7 inhibitors which can be used in the treatment of cell proliferative disorders, such as cancer. Additionally, there is a need to provide CDK7 inhibitors which are selective for CDK7 compared to other CDKs.

The present invention provides novel compounds that are selective CDK7 inhibitors. Such new compounds could address the need for potent, effective treatment of cancer, especially cancer with deregulated transcription. The present invention could also address the need for potent, effective treatment of urothelial cancer, uterine cancer, colorectal cancer, breast cancer, lung cancer, ovarian cancer, gastric cancer, hepatobiliary cancer, pancreatic cancer, cervical cancers, prostate cancer, haemotological cancers, sarcomas, skin cancers, and/or gliomas.

The present invention provides a compound of formula:

or a pharmaceutically acceptable salt thereof. Especially preferred is a besylate salt. Also preferred is the hemi-edisylate hydrate salt.

The present invention also provides a method for the treatment of cancer, in particular for the treatment of cancer with deregulated transcription. Preferably, the cancer is urothelial cancer, uterine cancer, colorectal cancer, breast cancer, lung cancer, ovarian cancer, gastric cancer, hepatobiliary cancer, pancreatic cancer, cervical cancers, prostate cancer, haemotological cancers, sarcomas, skin cancers, or gliomas. More preferably, the cancer is colorectal cancer, breast cancer, lung cancer, ovarian cancer, or gastric cancer. Most preferably, the cancer is breast cancer.

The present invention also provides a method of treating urothelial cancer, uterine cancer, colorectal cancer, breast cancer, lung cancer, ovarian cancer, gastric cancer, hepatobiliary cancer, urothelial cancer, uterine cancer, colorectal cancer, breast cancer, lung cancer, ovarian cancer, gastric cancer, hepatobiliary cancer, pancreatic cancer, cervical cancers, prostate cancer, haemotological cancers, sarcomas, skin cancers, or gliomas in a patient, comprising testing for the presence of at least one loss of function mutation in the ARID1A, KMT2C, KMT2D and/or RB1 genes in a biological sample from the patient and administering a therapeutically effective amount of [(3S)-1-[(E)-4-(dimethylamino)but-2-enoyl]pyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate or a pharmaceutically acceptable salt thereof to the patient if the sample tests positive for at least one loss of function mutation in any of the ARID1A, KMT2C, KMT2D and/or RB1 genes. Preferably, the salt is a besylate salt or a hemi-edisylate hydrate salt. More preferably, the cancer is colorectal cancer, breast cancer, lung cancer, ovarian cancer, or gastric cancer. Most preferably, the cancer is breast cancer. Preferably, the biological sample is a tumor sample and the sample is assayed by genomic/DNA sequencing. Preferably, the sample is obtained from the patient prior to a first administration of [(3S)-1-[(E)-4-(dimethylamino)but-2-enoyl]pyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate or a pharmaceutically acceptable salt thereof to the patient. Preferably, the salt is a besylate salt or a hemi-edisylate hydrate salt. Preferably, the gene is the ARID1A gene. Preferably, the gene is the KMT2C gene. Preferably, the gene is the KMT2D gene. Preferably, the gene is the RB1 gene.

The present invention also provides a method of treating urothelial cancer, uterine cancer, colorectal cancer, breast cancer, lung cancer, ovarian cancer, gastric cancer, hepatobiliary cancer, pancreatic cancer, cervical cancers, prostate cancer, haemotological cancers, sarcomas, skin cancers, or gliomas in a patient, comprising administering a therapeutically effective amount of [(3S)-1-[(E)-4-(dimethylamino)but-2-enoyl]pyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate or a pharmaceutically acceptable salt thereof to the patient provided that a biological sample from the patient contains at least one loss of function mutation in the ARID1A, KMT2C, KMT2D and/or RB1 genes. Preferably, the salt is a besylate salt of a hemi-edisylate hydrate salt. More preferably, the cancer is colorectal cancer, breast cancer, lung cancer, ovarian cancer, or gastric cancer. Most preferably, the cancer is breast cancer. Preferably, the biological sample is a tumor sample and the sample is assayed by genomic/DNA sequencing. Preferably, the sample is obtained from the patient prior to a first administration of [(3S)-1-[(E)-4-(dimethylamino)but-2-enoyl]pyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate or a pharmaceutically acceptable salt thereof to the patient. Preferably, the salt is a besylate salt or a hemi-edisylate hydrate salt. Preferably, the gene is the ARID1A gene. Preferably, the gene is the KMT2C gene. Preferably, the gene is the KMT2D gene. Preferably, the gene is the RB1 gene.

The present invention also provides a method of treating urothelial cancer, uterine cancer, colorectal cancer, breast cancer, lung cancer, ovarian cancer, gastric cancer, hepatobiliary cancer, pancreatic cancer, cervical cancers, prostate cancer, haemotological cancers, sarcomas, skin cancers, or gliomas in a patient, comprising administering a therapeutically effective amount of [(3S)-1-[(E)-4-(dimethylamino)but-2-enoyl]pyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate or a pharmaceutically acceptable salt thereof to a patient provided that the patient is selected for treatment if a biological sample from the patient tested positive for at least one loss of function mutation in the ARID1A, KMT2C, KMT2D and/or RB1 genes. Preferably, the salt is a besylate salt or a hemi-edisylate hydrate salt. More preferably, the cancer is selected from the group consisting of colorectal cancer, breast cancer, lung cancer, ovarian cancer, or gastric cancer. Most preferably, the cancer is breast cancer. Preferably, the biological sample is a tumor sample and the sample is assayed by genomic/DNA sequencing. Preferably, the sample is obtained from the patient prior to a first administration of [(3S)-1-[(E)-4-(dimethylamino)but-2-enoyl]pyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate or a pharmaceutically acceptable salt thereof to the patient. Preferably, the salt is a besylate salt or hemi-edisylate hydrate salt. Preferably, the gene is the ARID1A gene. Preferably, the gene is the KMT2C gene. Preferably, the gene is the KMT2D gene. Preferably, the gene is the RB1 gene.

The present invention also provides a pharmaceutical composition comprising a compound of the invention, or a pharmaceutically acceptable salt thereof, in combination with one or more pharmaceutically acceptable carriers, diluents, or excipients. In a further embodiment, the composition further comprises one or more other therapeutic agents. In a further embodiment, the present invention provides a pharmaceutical composition for the treatment of cancer comprising a compound of the invention, or a pharmaceutically acceptable salt thereof, in combination with one or more pharmaceutically acceptable carriers, diluents, or excipients. In yet a further embodiment, the present invention provides a pharmaceutical composition for the treatment of cancer with deregulated transcription comprising a compound of the invention, or a pharmaceutically acceptable salt thereof, in combination with one or more pharmaceutically acceptable carriers, diluents, or excipients. In said embodiments, the cancer is urothelial cancer, uterine cancer, colorectal cancer, breast cancer, lung cancer, ovarian cancer, gastric cancer, hepatobiliary cancer, pancreatic cancer, cervical cancers, prostate cancer, haemotological cancers, sarcomas, skin cancers, or gliomas.

In a preferred embodiment, the cancer is colorectal cancer, breast cancer, lung cancer, ovarian cancer, or gastric cancer. In a more preferred embodiment, the cancer is breast cancer.

Further, the present invention provides a compound of the invention or a pharmaceutically acceptable salt thereof, for use in the treatment of cancer also comprising performing an in vitro assay using a biological sample from the patient, determining the presence of at least one inactivating mutation in the ARID1A, KMT2C, KMT2D and RB1 genes, and administering a therapeutically effective amount of the compound or salt thereof to the patient if at least one inactivating mutation in any of the genes is present. In said embodiment, the cancer is for use in the treatment of urothelial cancer, uterine cancer, colorectal cancer, breast cancer, lung cancer, ovarian cancer, gastric cancer, hepatobiliary cancer, pancreatic cancer, cervical cancers, prostate cancer, haemotological cancers, sarcomas, skin cancers, or gliomas. Preferably, the biological sample is a tumor sample and the sample is assayed by genomic/DNA sequencing. Preferably, the compound of salt thereof is administered to the patient at a dose of about 1 mg to 2 g. Preferably, the sample is obtained from the patient prior to the first administration of the compound or the salt thereof to the patient. Preferably, a patient is selected for having an inactivating mutation in the ARID1A gene. Preferably, the patient is selected for having an inactivating mutation in the KMT2C gene. Preferably, a patient is selected for having an inactivating mutation in the KMT2D gene. Preferably, a patient is selected for having an inactivating mutation in the RB1 gene.

Further, the present invention provides a compound of the invention, or a pharmaceutically acceptable salt thereof, for use in therapy, in particular for the treatment of cancer with deregulated transcription. In a further embodiment, the present invention provides the use of a compound of the invention, or a pharmaceutically acceptable salt thereof, for the manufacture of a medicament for the treatment of cancer with deregulated transcription. In said embodiments, the cancer is urothelial cancer, uterine cancer, colorectal cancer, breast cancer, lung cancer, ovarian cancer, gastric cancer, hepatobiliary cancer, pancreatic cancer, cervical cancers, prostate cancer, haemotological cancers, sarcomas, skin cancers, or gliomas. In a preferred embodiment, the cancer is selected colorectal cancer, breast cancer, lung cancer, ovarian cancer, or gastric cancer. In a more preferred embodiment, the cancer is breast cancer.

In yet a further embodiment, the present invention provides a compound of the invention, or a pharmaceutically acceptable salt thereof, for use in therapy, in particular for the treatment of cancer. In a further embodiment, the present invention provides the use of a compound of the invention, or a pharmaceutically acceptable salt thereof, for the manufacture of a medicament for the treatment of cancer. In said embodiments, the cancer is urothelial cancer, uterine cancer, colorectal cancer, breast cancer, lung cancer, ovarian cancer, gastric cancer, hepatobiliary cancer, pancreatic cancer, cervical cancers, prostate cancer, haemotological cancers, sarcomas, skin cancers, or gliomas. In a preferred embodiment, the cancer is colorectal cancer, breast cancer, lung cancer, ovarian cancer, or gastric cancer. In a more preferred embodiment, the cancer is breast cancer. Further, the present invention provides for the manufacture of a medicament for the treatment of a urothelial cancer, uterine cancer, colorectal cancer, breast cancer, lung cancer, ovarian cancer, gastric cancer, hepatobiliary cancer, pancreatic cancer, cervical cancers, prostate cancer, haemotological cancers, sarcomas, skin cancers, or gliomas, also comprising performing an in vitro assay using a biological sample from the patient, determining the presence of at least one inactivating mutation in the ARID1A, KMT2C, KMT2D and RB1 genes, and administering a therapeutically effective amount of the compound or salt thereof to the patient if at least one inactivating mutation in any of the genes is present. Preferably, the biological sample is a tumor sample and the sample is assayed by genomic/DNA sequencing. Preferably the compound of salt thereof is administered to the patient at a dose of about 1 mg to 2 g. Preferably, the sample is obtained from the patient prior to the first administration of the compound or the salt thereof to the patient. Preferably, a patient is selected for having at least one inactivating mutation in the ARID1A gene. Preferably, a patient is selected for having at least one inactivating mutation in the KMT2C gene. Preferably, a patient is selected for having at least one inactivating mutation in the KMT2D gene. Preferably, a patient is selected for having at least one inactivating mutation in the RB1 gene.

The present invention provides a compound of the invention [(3S)-1-[(E)-4-(dimethylamino)but-2-enoyl]pyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate in a crystalline salt form. The present invention also provides crystalline [(3S)-1-[(E)-4-(dimethylamino)but-2-enoyl]pyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate hemi-edisylate hydrate. The present invention also provides [(3S)-1-[(E)-4-(dimethylamino)but-2-enoyl]pyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate hemi-edisylate hydrate in a crystalline form characterized by a X-ray powder diffraction pattern having characteristic peaks using CuKa radiation, in 2θ±0.2°, occurring at 18.5° in combination with one or more peaks selected from the group consisting of 21.5°, 16.7°, and 15.2°. The present invention also provides crystalline [(3S)-1-[(E)-4-(dimethylamino)but-2-enoyl]pyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate besylate. The present invention also provides [(3S)-1-[(E)-4-(dimethylamino)but-2-enoyl]pyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate besylate in a crystalline form characterized by a X-ray powder diffraction pattern having characteristic peaks using CuKa radiation, in 2θ±0.2°, occurring at 21.5° in combination with one or more peaks selected from the group consisting of 12.4°, 17.3°, and 15.8°. The present invention also provides crystalline [(3S)-1-[(E)-4-(dimethylamino)but-2-enoyl]pyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate hydrochloride. The present invention also provides [(3S)-1-[(E)-4-(dimethylamino)but-2-enoyl]pyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate hydrochloride in a crystalline form characterized by a X-ray powder diffraction pattern having characteristic peaks using CuKa radiation, in 2θ±0.2°, occurring at 18.9° in combination with one or more peaks selected from the group consisting of 5.5°, 15.5°, and 9.7°.

The present invention also encompasses intermediates and processes useful for the synthesis of a compound of the present invention.

The term “treating” (or “treat” or “treatment”) as used herein refers to restraining, slowing, stopping, or reversing the progression or severity of an existing symptom, condition or disorder.

As used herein, the terms “cancer” and “cancerous” refer to or describe the physiological condition in patients that is typically characterized by unregulated cell proliferation. Included in this definition are benign and malignant cancers. By “early stage cancer” or “early stage tumor” is meant a cancer that is not advanced or metastatic or is classified as a Stage 0, I, or II cancer. Examples of cancer include, but are not limited to, urothelial cancer, uterine cancer, colorectal cancer, breast cancer, lung cancer, ovarian cancer, gastric cancer, hepatobiliary cancer, pancreatic cancer, cervical cancers, prostate cancer, haemotological cancers, sarcomas, skin cancers, or gliomas.

A compound of the present invention may react to form pharmaceutically acceptable salts. Pharmaceutically acceptable salts and common methodology for preparing them are well known in the art (see, e.g., P. Stahl, et al. Handbook of Pharmaceutical Salts: Properties, Selection and Use, 2^(nd) Revised Edition (Wiley-VCH, 2011); S. M. Berge, et al., “Pharmaceutical Salts,” Journal of Pharmaceutical Sciences, Vol. 66, No. 1, January 1977).

The skilled artisan will appreciate that a compound of the invention, as shown in (I), or pharmaceutically acceptable salt thereof, is comprised of a core that contains one chiral center, as represented by * below:

Although the present invention contemplates all individual enantiomers, as well as mixtures of the enantiomers of said compounds including racemates, the preferred compound of the invention is represented by (II) below:

or pharmaceutically acceptable salts thereof.

The skilled artisan will also appreciate that the Cahn-Ingold-Prelog (R) or (S) designations for all chiral centers will vary depending upon the substitution patterns of the particular compound. The single enantiomers may be prepared beginning with chiral reagents or by stereoselective or stereospecific synthetic techniques. Alternatively, the single enantiomers may be isolated from mixtures by standard chiral chromatographic or crystallization techniques at any convenient point in the synthesis of compounds of the invention. Single enantiomers of compounds of the invention are a preferred embodiment of the invention.

A compound of the present invention is preferably formulated as pharmaceutical compositions administered by a variety of routes. Such pharmaceutical compositions and processes for preparing the same are well known in the art (see, e.g., Remington: The Science and Practice of Pharmacy (A. Gennaro, et al., eds., 21st ed., Mack Publishing Co., 2005)). More particularly preferred, is a pharmaceutical composition comprising a compound of the formula,

or a pharmaceutically acceptable salt thereof and one or more pharmaceutically acceptable carriers or diluents.

A preferred embodiment of the present invention is

or a pharmaceutically acceptable salt thereof.

An especially preferred embodiment of the present invention relates to the compound, (3S)-1-[(2E)-4-(Dimethyl amino)but-2-enoyl]pyrrolidin-3-yl 4-{[5-methyl-3-(propan-2-yl)pyrazolo[1,5-a]pyrimidin-7-yl]amino}piperidine-1-carboxylate:

or a pharmaceutically acceptable salt thereof. Especially preferred in the hemi-edisylate hydrate salt or besylate salt.

Another especially preferred embodiment of the present invention relates to the compound, (3S)-1-[(2E)-4-(Dimethyl amino)but-2-enoyl]pyrrolidin-3-yl 4-{[5-methyl-3-(propan-2-yl)pyrazolo[1,5-A]pyrimidin-7-yl]amino}piperidine-1-carboxylate:

A further especially preferred embodiment of the present invention relates to the compound, (3R)-1-[(2E)-4-(Dimethylamino)but-2-enoyl]pyrrolidin-3-yl 4-{[5-methyl-3-(propan-2-yl)pyrazolo[1,5-A]pyrimidin-7-yl]amino}piperidine-1-carboxylate (as shown by (III) below):

or a pharmaceutically acceptable salt thereof. Especially preferred in the hemi-edisylate hydrate salt or besylate salt.

Another especially preferred embodiment of the present invention relates to the compound, (3R)-1-[(2E)-4-(Dimethylamino)but-2-enoyl]pyrrolidin-3-yl 4-{[5-methyl-3-(propan-2-yl)pyrazolo[1,5-A]pyrimidin-7-yl]amino}piperidine-1-carboxylate:

The compounds of the present invention are generally effective over a wide dosage range. For example, dosages per day fall within the range of about 1 mg to about 2 g. In some instances dosage levels below the lower limit of the aforesaid range may be more than adequate, while in other cases still larger doses may be employed while maintaining a favorable benefit/risk profile, and therefore the above dosage range is not intended to limit the scope of the invention in any way. It will be understood that the amount of the compound actually administered will be determined by a physician, in light of the relevant circumstances, including the condition to be treated, the chosen route of administration, the actual compound or compounds administered, the age, weight, and response of the individual patient, and the severity of the patient's symptoms.

Individual isomers and enantiomers may be separated or resolved by one of ordinary skill in the art at any convenient point in the synthesis of compounds of the invention, by methods such as selective crystallization techniques or chiral chromatography (see, for example, J. Jacques, et al., “Enantiomers, Racemates, and Resolutions”, John Wiley and Sons, Inc., 1981, and E. L. Eliel and S. H. Wilen, “Stereochemistry of Organic Compounds”, Wiley-Interscience, 1994).

Additionally, certain intermediates described herein may contain one or more protecting groups. The variable protecting group may be the same or different in each occurrence depending on the particular reaction conditions and the particular transformations to be performed. The protection and deprotection conditions are well known to the skilled artisan and are described in the literature (See for example “Greene's Protective Groups in Organic Synthesis”, Fourth Edition, by Peter G. M. Wuts and Theodora W. Greene, John Wiley and Sons, Inc. 2007).

Certain abbreviations are defined as follows: “¹H NMR” refers to ¹H-nuclear magnetic resonance; “eq” refers to equivalent; “THF” refers to tetrahydrofuran; “DCM” refers to dichloromethane; “MeCN” or “ACN” refers to acetonitrile; “DMSO” refers to dimethyl sulfoxide; “MTBE” refers to methyl tert-butyl ether; “TEA” refers to trimethylamine; “HATU” refers to I-[Bis(dimethylamino)methylene]-I 8-1,2,3-triazolo[4, 5-b]pyridinium 3-oxid-hexafluorophosphate; “MeOH” refers to methanol; “TLC” refers to thin layer chromatography; “UV” refers to ultraviolet; “LC Column” refers to liquid chromatography column; “DMEA” refers to dimethylmethylamine; “EtOAc” refers to ethyl aetate; “DMF” refers to dimethylformamide; “SCX” refers to strong cation exchange; “ca.” refers to about or approximately; “RBF” refers to round bottom flask; “ATP” refers to adenosine triphosphate; “DTT” refers to dithiothreitol; “HEPES” refers to (4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid); “EDTA” refers to Ethylenediaminetetraacetic acid; “ATCC” refers to American Type Culture Collection; “RT” refers to room temperature; “PBS” refers to phosphate-buffered saline; “BSA” refers to bovine serum albumin; “FBS refers to fetal bovine serum; “RNAase” refers to ribonuclease; “cDNA” refers to complementary DNA; “GST” refers to glutathione S-transferase; “His” refers to histidine; “GSH” refers to glutathione; and “HBSS” refers to Hank's Balanced Salt Solution.

The compounds of the invention, or pharmaceutically acceptable salts thereof, may be prepared by a variety of procedures known in the art, as well as the Preparations and Examples below. The specific synthetic steps for each of the routes described may be combined in different ways, or in conjunction with steps from different schemes, to prepare compounds of the invention, or pharmaceutically acceptable salts thereof. The products of each step in the schemes below can be recovered by conventional methods well known in the art, including extraction, evaporation, precipitation, chromatography, filtration, trituration, and crystallization. The reagents and starting materials are readily available to one of ordinary skill in the art.

The following preparations and examples further illustrate the invention and represent typical synthesis of the compounds of the present invention.

PREPARATIONS AND EXAMPLES Preparation 1 Synthesis of 3-isopropylpyrazolo[1,5-a]pyrimidine-5,7-diol

Add sodium ethoxide (979 g, 14.4 moles, 3.0 eq) and diethyl malonate (998 g, 6.23 moles, 3.0 eq) at 23° C. to a solution of 4-isopropyl-1H-pyrazol-3-amine (600 g, 4.79 moles) in ethanol (4.2 L) and heat the mixture to 80° C. (internal temperature) for 15 hours. Cool the mixture to 25° C., add 1 M aq. HCl (2.0 L) (final pH=2.0), filter, wash the solid with water (2.0 L), and dry to obtain 3-isopropylpyrazolo[1,5-a]pyrimidine-5,7-diol (600 g, 65%) as a white solid. ES/MS m/z 194 (M+H).

Preparation 2 Synthesis of 5,7-dichloro-3-isopropyl-pyrazolo[1,5-a]pyrimidine

Add POCl₃ (2.00 L, 25.8 moles, 10 eq) and N,N-dimethylaniline (162 mL, 2.58 moles, 1.0 eq) to a suspension of 3-isopropylpyrazolo[1,5-a]pyrimidine-5,7-diol (500 g, 2.58 moles) in MeCN (1.25 L) at 50° C. and heat the mixture to 100° C. for 36 hours. Cool to 23° C., pour dropwise into 1:1 ice/phosphate buffer (1 M, pH=8, 10 L) and stir for 15 hours. Filter, wash the solid with water (5.0 L) and dry to obtain 5,7-dichloro-3-isopropyl-pyrazolo[1,5-a]pyrimidine (375 g, 63%) as a brown solid. ES/MS m/z (³⁵Cl/³⁷Cl) 230/232 (M+H). ¹H NMR (d₆-DMSO) δ 1.32 (d, 6H), 3.19 (dq, 1H), 7.58 (s, 1H), 8.31 (s, 1H).

Alternative Synthesis of 5,7-dichloro-3-isopropyl-pyrazolo[1,5-a]pyrimidine

Add sodium ethoxide—21% in ethanol—(17.9 mL, 47.9 mmol) to a solution of 4-isopropyl-1H-pyrazol-5-amine (5 g, 39.9 mmol) and diethyl malonate (6.74 mL, 43.9 mmol) in ethanol (150 mL) and stir at RT. After 5 minutes, heat at 90° C. and stir. After 18 hours, cool to RT and concentrate under reduce pressure. Dissolve the residue with water and add 1 N hydrochloric acid to pH=3. Filter the white precipitate and dry under reduced pressure at 50° C. for 18 hours. Suspend the resulting solid, 3-isopropylpyrazolo[1,5-a]pyrimidine-5,7-diol (4.92 g, 25.5 mmol, 0.638) in phosphorous oxychloride (48 mL) and add N,N-dimethylaniline (2.3 mL). Reflux the mixture at 110° C. After 2 hours, cool to RT and concentrate under reduced pressure. Pour the residue onto an ice/water solution and extract with DCM (twice). Combine the organic layers and wash with brine, dry over magnesium sulfate. Filter, and concentrate under reduced pressure to give a residue. Purify the residue by flash chromatography (silica gel), eluting with ethyl hexane: acetate to provide 5,7-dichloro-3-isopropyl-pyrazolo[1,5-a]pyrimidine (4.45 g, 19.3 mmol) as a brown solid. MS (m/z): 230, 232 (M+1). ¹H NMR (400.21 MHz, DMSO): 8.31 (s, 1 H), 7.58 (s, 1 H), 3.19 (m, 1 H), 1.32 (d, J=7.0 Hz, 6H).

Preparation 3 Synthesis of tert-butyl 4-[(5-chloro-3-isopropyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate

Add N,N-diisopropylethylamine (189 mL, 140 g, 1080 mmol, 2 eq) and tert-butyl 4-aminopiperidine-1-carboxylate (114 g, 570 mmol, 1.05 eq) to a suspension of 5,7-dichloro-3-isopropyl-pyrazolo[1,5-a]pyrimidine (130 g, 542 mmol) in 2-propanol (1.0 L) at 23° C. and stir the mixture for 18 hours. filter, wash the solid with MTBE (200 mL), and dry to obtain tert-butyl 4-[(5-chloro-3-isopropyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate (182 g, 85% yield) as a yellow solid. ES/MS m/z (³⁵Cl/³⁷Cl) 394/396 (M+H). ¹H NMR (d₆-DMSO) δ 1.28 (d, 6H), 1.42 (s, 9H), 1.61 (m, 2H), 1.83 (m, 2H), 2.87 (m, 1H), 3.10 (dq, 1H), 3.32 (m, 1H), 3.85 (m, 1H), 3.98 (m, 2H), 6.34 (s, 1H), 8.01 (s, 1H), 8.07 (d, 1H).

Preparation 4 Synthesis of tert-butyl 4-[tert-butoxycarbonyl-(5-chloro-3-isopropyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate

Add N,N-diisopropylethylamine (69.1 mL, 51.2 g, 396 mmol, 1 eq), 4-dimethylaminopyridine (4.84 g, 39.6 mmol, 0.1 eq), and di-tert-butyl dicarbonate (200 mL, 190 g, 871 mmol, 2.2 eq) to a solution of tert-butyl 4-[(5-chloro-3-isopropyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate (156 g, 396 mmol) in THF (936 mL) at 23° C., and heat the mixture at 50° C. (internal temperature) for 21 hours. Cool to 23° C. and concentrate in vacuo to obtain tert-butyl 4-[tert-butoxycarbonyl-(5-chloro-3-isopropyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate (195 g, 99%) as an orange solid. ES/MS m/z (³⁵Cl/³⁷Cl) 438/440 (M+H-56). ¹H NMR (d₆-DMSO) δ 1.20 (s, 9H), 1.31 (d, 6H), 1.35 (s, 9H), 1.46 (m, 2H), 1.88 (m, 2H), 2.75 (m, 1H), 3.19 (dq, 1H), 3.32 (m, 1H), 3.95 (m, 1H), 4.18 (m, 2H), 7.20 (s, 1H), 8.19 (s, 1H).

Alternative Synthesis of tert-butyl 4-[tert-butoxycarbonyl-(5-chloro-3-isopropyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate

Add tert-butyl 4-aminopiperidine-1-carboxylate (2.8 g, 14 mmol) to a solution of 5,7-dichloro-3-isopropyl-pyrazolo[1,5-a]pyrimidine (3.1 g, 13 mmol) in ethanol (32 mL). Heat at 80° C. After 18 hours, cool to RT and concentrate under reduced pressure. Purify the residue by flash chromatography (silica gel), eluting with ethyl acetate:DCM to provide tert-butyl 4-[tert-butoxycarbonyl-(5-chloro-3-isopropyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate as a white solid. Mass spectrum (m/e): 394, 396 (M+1) Add tert-butoxycarbonyl tert-butyl carbonate (1.14 g, 5.22 mmol) to a solution of tert-butyl 4-[(5-chloro-3-isopropyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate (940 mg, 2.386 mmol) and 4-dimethylaminopyridine (290 mg, 2.33 mmol) in THF (7 mL). Heat the mixture at 60° C. After 30 minutes, cool to RT and concentrate under reduced pressure. Purify the residue by flash chromatography (silica gel), eluting with DCM to provide tert-butyl 4-[tert-butoxycarbonyl-(5-chloro-3-isopropyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate (1.1 g) as a yellowish oil. Mass spectrum (m/z): 438 (M-t-Bu). ¹H NMR (400.13 MHz, d₆-DMSO): 8.19 (s, 1H), 7.20 (s, 1H), 5.76 (s, 1H), 4.17 (m, 1H), 3.95 (m, 2 H), 3.19 (m, 1 H), 1.87 (m, 2 H), 1.47 (m, 2 H), 1.35 (s, 9 H), 1-31 (d, 6H), 1.19 (s, 9H).

Preparation 5 Synthesis of tert-butyl 4-[tert-butoxycarbonyl-(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate

Add [1,1′-bis(diphenylphosphino)ferrocene]dichloropalladium (II) DCM adduct (15.7 g, 19.3 mmol, 0.05 eq), potassium phosphate tribasic (245 g, 1160 mmol, 3 eq), and 2,4,6-trimethyl-1,3,5,2,4,6-trioxatriborinane (50 mass % in THF, 75.3 mL, 67.6 g, 270 mmol, 0.7 eq) to a solution of tert-butyl 4-[tert-butoxycarbonyl-(5-chloro-3-isopropyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate (190 g, 385 mmol) in 1,4-dioxane (1.5 L) at 90° C. (internal temperature). After 5 days, cool to 23° C., filter through a pad of diatomaceous earth, and rinse the solid with THF (3×250 mL). Treat combined filtrates at 23° C. with SiliaMetS® Thiol resin (40-63 μm; loading=1.46 mmol/g; 320 g, 467 mmol), and heat to 65° C. for 18 hours. Cool to 23° C., filter, and wash resin with DCM (2×250 mL). Concentrate combined filtrates in vacuo, dissolve the residue in MTBE (1 mL), wash with water (200 mL), dry (MgSO₄), and concentrate in vacuo to obtain tert-butyl 4-[tert-butoxycarbonyl-(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate (182 g, 100%) as a brown solid. ES/MS m/z 474 (M+H).

Preparation 6 Synthesis of 3-isopropyl-5-methyl-N-(4-piperidyl)pyrazolo[1,5-a]pyrimidin-7-amine dihydrochloride

Add hydrochloric acid in 2-propanol (5.50 mol/L, 349 mL, 1920 mmol, 5 eq) to a suspension of tert-butyl 4-[tert-butoxycarbonyl-(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate (182 g, 384 mmol) in 2-propanol (1.4 L) at 23° C., and heat the mixture to 70° C. (internal temperature) for 3 hours. Cool to 23° C., filter, wash the solid with MTBE (2×200 mL) and dry to obtain 3-isopropyl-5-methyl-N-(4-piperidyl)pyrazolo[1,5-a]pyrimidin-7-amine dihydrochloride (95 g, 71% yield) as a yellow solid. Combine mother liquors, dilute with MTBE (2 L), filter, wash the solid with MTBE (2×50 mL), and dry to obtain additional material (8.42 g, 15% yield). ES/MS m/z 274 (M+H). ¹H NMR (d₆-DMSO) δ 1.28 (d, 6H), 2.04 (m, 4H), 2.61 (s, 3H), 3.00 (m, 2H), 3.40 (m, 3H), 4.16 (m, 2H), 6.68 (s, 1H), 8.30 (s, 1H), 8.80 (m, 1H), 9.21 (m, 1H), 9.86 (m, 1H).

Alternative Synthesis of 3-isopropyl-5-methyl-N-(4-piperidyl)pyrazolo[1,5-a]pyrimidin-7-amine dihydrochloride

Dissolve 7-chloro-3-isopropyl-5-methylpyrazolo[1,5-a]pyrimidine (2.1 kg, 10.0 mol) and diisopropylethylamine (4.18 L, 2.4 eq) in isopropanol (16.8 L, 8 mL/g). Charge tert-butyl 4-aminopiperidine-1-carboxylate (2.6 kg, 1.3 eq.) to the reaction mixture and heat to 75-80° C. for 16 hours. Cool reaction mixture to 5-10° C. and add a 4 M solution of hydrochloric acid in isopropanol (17.5 L, 7.0 eq). Heat to 40-45° C. for 4 hours. Cool to 25-30° C. and filter the mixture to afford the title compound (2.25 kg, 72.7% yield). Material was used in next step without further purification. ¹H NMR (500 MHz, D₂O) δ 8.16 (s, 1H), 6.45 (s, 1H), 4.29-4.26 (m, 1 H), 3.63 (d, J=15.0 Hz, 2H), 3.26-3.12 (m, 3H), 2.64 (s, 3H), 2.40 (d, J=15.0 Hz, 2H), 2.08 (dd, J=10.0, 25.0 Hz, 2H), 1.31 (d, J=5.0 Hz, 6H).

Alternative Synthesis of 3-isopropyl-5-methyl-N-(4-piperidyl)pyrazolo[1,5-a]pyrimidin-7-amine as Free Base

Add 1,4-dioxane (15 mL) to a mixture of tert-butyl 4-[tert-butoxycarbonyl-(5-chloro-3-isopropyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate (689 mg, 1.39 mmol), 2,4,6-trimethyl-1,3,5,2,4,6-trioxatriborinane (350 mg, 2.79 mmol) and potassium phosphate tribasic (1.2 g, 5.5 mmol,). Bubble N₂ on to the solution for 5 minutes. Add [1,1′-bis(diphenylphosphino)ferrocene]dichloropalladium(II) DCM adduct (60 mg, 0.072 mmol). Heat at 110° C. After, 1.5 hours add more [1,1-bis(diphenylphosphino)ferrocene]dichloropalladium(II) (60 mg, 0.072 mmol) and heat at 100° C. After 18 hours, cool to RT, filter the mixture through a pad of filter cell, rinse with ethyl acetate and concentrate under reduced pressure. Purify the residue by flash chromatography (silica gel), eluting with ethyl acetate and DCM to provide tert-butyl 4-[tert-butoxycarbonyl-(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate (537 mg, 1.077 mmol) as an orangeish oil. Mass spectrum (m/z): 474 (M+1).

Add trifluoroacetic acid (2.5 mL, 33 mmol) dropwise to a solution of tert-butyl 4-[tert-butoxycarbonyl-(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate (537 mg, 1.077 mmol) in DCM (12 mL). Stir at RT. After 2 hours, concentrate the mixture under reduce pressure. Purify the residue by SCX-2 cartridge elution with 10% DCM: MeOH then MeOH (2 N NH₃). Concentrate the basic fraction under reduced pressure to provide 3-isopropyl-5-methyl-N-(4-piperidyl)pyrazolo[1,5-a]pyrimidin-7-amine (345 mg, 1.199 mmol) as a brownish solid. Mass spectrum (m/z): 274 (M+1). ¹H NMR (400.13 MHz, DMSO): 7.82 (s, 1 H), 7.23 (d, 1H), 6.08 (s, 1 H), 3.58 (m, 1 H), 3.12 (m, 1 H), 2.97 (m, 2 H), 2.58 (m, 2 H), 2.39 (s, 3 H), 2.10 (m, 2 H), 1.28 (d, 6 H).

Preparation 7 Synthesis of [(3S)-1-tert-butoxycarbonylpyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate

Add phosgene (20 mass % in toluene, 348 mL, 485 g, 981 mmol, 2.4 eq) to a solution of tert-butyl (3S)-3-hydroxypyrrolidine-1-carboxylate (76.5 g, 409 mmol) in THF (765 mL) placed in a 3 neck RBF connected to a scrubber trap bottle containing 32% aqueous NH₄OH, at 23° C. for 1 hour. Bubble N₂ through the mixture for 30 minutes, and concentrate in vacuo. Dissolve the residue in DCM (757 mL), cool to 0° C. (internal temperature), and add (slow addition over 7 minutes) a suspension of 3-isopropyl-5-methyl-N-(4-piperidyl)pyrazolo[1,5-a]pyrimidin-7-amine dihydrochloride (94.6 g, 273.2 mmol) in DCM (756.8 mL), previously treated with triethylamine (228 mL, 166 g., 1639 mmol, 6 eq). Remove the cooling bath after addition, and quench the reaction after 30 minutes with 35% aqueous HCl (20 mL) and 1 M aqueous HCl (300 mL) (final pH=7). Separate the organic layer, wash with water (300 mL) and saturated aqueous NaCl (300 mL), dry (MgSO₄), and concentrated in vacuo. Dissolve the residue (ca. 180 g) in DCM (1.5 L), add SiliaMetS® Thiol resin (40-63 μm; loading=1.46 mmol/g; 10 g, 14.6 mmol, 140 eq based on Pd content) at 23° C., and then heat the mixture to 40° C. for 2 hours. Filter, rinse the resin with DCM (2×10 mL), and concentrate combined filtrates in vacuo to obtain [(3S)-1-tert-butoxycarbonylpyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate (129 g, 97%) as a yellow solid. ES/MS m/z 487 (M+H). ¹H NMR (d₆-DMSO) δ 1.28 (d, 6H), 1.40 (s, 9H), 1.65 (m, 2H), 1.88 (m, 2H), 1.96 (m, 1H), 2.07 (m, 1H), 2.46 (s, 3H), 2.90 (m, 2H), 3.31 (m, 5H), 3.89 (m, 1H), 4.02 (m, 2H), 5.10 (m, 1H), 6.32 (s, 1H), 8.01 (s, 1H).

Alternative Synthesis of [(3S)-1-tert-butoxycarbonylpyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate

Dissolve tert-butyl (3S)-3-hydroxypyrrolidine-1-carboxylate (438 g, 1.3 eq.) in ACN (4.4 L, 10.0 mL/g) at 15-30° C. Add triethylamine (595 mL, 4.5 eq.) followed by 4-nitrophenyl chloroformate (490 g, 1.4 eq.) at 15-30° C. Heat to 35-40° C. and stir mixture for 4 hours. Cool to 15-25° C. and add 3-isopropyl-5-methyl-N-(piperidin-4-yl)pyrazolo[1,5-a]pyrimidin-7-amine (500 g, 1.8 mol). Stir at 15-30° C. for 5 hours. Concentrate under reduced pressure. Add 2-methyltetrahydrofuran (4.4 L, 10.0 mL/g), stir, and filter. Wash filtrate sequentially with 2 M NaOH (1.1 L, 2.5 mL/g, 4 times) and saturated aqueous NaCl (4.4 L, 10.0 mL/g). Dry over Na₂SO₄, filter, and concentrate under reduced pressure. Add isopropyl alcohol (2.2 L, 5 mL/g) to obtain a solution of title compound (660 g, 75.4% yield).

Preparation 8 Synthesis of [(3S)-pyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate

Add hydrochloric acid in 2-propanol (5.50 mol/L, 217 mL, 1190 mmol, 5 eq) to a suspension of [(3S)-1-tert-butoxycarbonylpyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate (116 g, 239 mmol) in 2-propanol (755 mL) at 23° C., and heat the mixture to 70° C. for 90 minutes. Cool to 23° C., and concentrate in vacuo. Suspend the residue in DCM (1.5 L), add 1 M aq. NaOH (400 mL) and 50% aq. NaOH (100 mL). Stir for 15 minutes. Separate the organic phase, dry (MgSO₄), and concentrate in vacuo. Suspend the residue (ca. 131 g) in MTBE/hexane (2:1, 900 mL), and stir the mixture for 18 hours. Filter, wash the filtered solid with hexane (2×100 mL), and dry to obtain [(3S)-pyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate (82.7 g, 90% yield) as a yellow solid. ES/MS m/z 387 (M+H). ¹H NMR (d₆-DMSO) δ 1.28 (d, 6H), 1.60 (m, 3H), 1.88 (m, 3H), 2.40 (s, 3H), 2.75 (m, 2H), 2.91 (m, 4H), 3.13 (dq, 1H), 3.78 (m, 1H), 4.02 (m, 2H), 5.10 (m, 1H), 6.14 (s, 1H), 7.41 (d, 1H), 7.87 (s, 1H).

Alternative Synthesis of [(3S)-pyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate

Add 5.5 M hydrochloric acid in isopropyl alcohol (8.4 L, 5.0 mL/g) to isopropyl alcohol solution containing (S)-1-(tert-butoxycarbonyl)pyrrolidin-3-yl 4-((3-isopropyl-5-methylpyrazolo[1,5-a]pyrimidin-7-yl)amino)piperidine-1-carboxylate (819 g) at 20-30° C. Heat reaction mixture to 50-60° C. for 5 hours. Cool to 30-35° C., add MTBE (8.2 L, 10 mL/g) and stir for 1 hour. Filter, add wet cake to aqueous sodium hydroxide (3.0 equiv) at 0-5° C. and stir for 30 minutes. Add 2-methyltetrahydrofuran (8.2 L, 10.0 mL/g) and stir. Extract organic phase and wash with saturated aqueous NaCl. Dry over sodium sulfate, filter, and concentrate under reduced pressure to 1-2 volumes. Add MTBE (2.46 L, 3 mL/g) and stir for 3 hours. Filtration affords the title compound (550 g). ¹H NMR (400 MHz, CDCl₃) δ 7.82 (s, 1H), 6.12 (d, J=8.1 Hz, 1H), 5.78 (s, 1H), 5.27-5.13 (m, 1H), 4.26-4.01 (m, 2H), 3.74-3.59 (m, 1H), 3.36-3.23 (m, 1H), 3.14-2.98 (m, 5H), 2.90 (ddd, J=11.1, 8.4, 5.4 Hz, 1H), 2.52 (s, 3H), 2.18-2.00 (m, 3H), 1.87 (dd, J=12.6, 6.4 Hz, 1H), 1.76 (s, 1H), 1.66-1.52 (m, 2H), 1.34 (d, J=6.9 Hz, 6H).

Alternative Synthesis of [(3S)-pyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate

Add phosgene (1.14 mL, 20 mass % in toluene, 3.20 mmol) to a cold (0° C.) solution of tert-butyl (3S)-3-hydroxypyrrolidine-1-carboxylate (500 mg, 2.67 mmol) and TEA (0.37 mL, 2.6 mmol) in THF (13 mL). Remove the cold bath and stir the mixture at RT. After 30 minutes, concentrate the mixture under reduced pressure and dissolve the residue in DCM (11 mL). Add this solution to a solution of 3-isopropyl-5-methyl-N-(4-piperidyl)pyrazolo[1,5-a]pyrimidin-7-amine (C, 365 mg, 100 mass %, 0.365 g) and TEA (0.3 mL) in DCM (11 mL). Stir the mixture at RT. After 10 minutes, add saturated aqueous NaHCO₃ solution and extract with more DCM. Combine the organic layers and wash with saturated aqueous NaCl, dry over magnesium sulfate, filter, and concentrate under reduced pressure to give a residue. Purify the residue by flash chromatography (silica gel), eluting with DCM: MeOH to provide [(3S)-1-tert-butoxycarbonylpyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate (671 mg) as a yellowish oil. Mass spectrum (m/z): 487 (M+1).

Add dropwise trifluoroacetic acid (2 mL, 26.45 mmol) to a solution of [(3S)-1-tert-butoxycarbonylpyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate (671 mg, 1.269 mmol) in DCM (12 mL). Stir at RT. After 18 hours, concentrate the mixture under reduced pressure. Dissolve the residue in DCM and wash the organic phase with 10% K₂CO₃ aqueous solution. Dry the organic phase over magnesium sulfate, filter and concentrate under reduced pressure to provide [(3S)-pyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate (274 mg, 0.6593 mmol) as a white foam. Mass spectrum (m/z): 387 (M+1). ¹H NMR (400.13 MHz, d₆-DMSO): 7.87 (s, 1H), 7.42 (d, J=9.0 Hz, 1H), 6.13 (s, 1H), 5.00 (ddd, J=9.0, 5.2, 2.5 Hz, 1H), 4.02 (m, 2H), 3.77 (m, 1 H), 3.13 (m, 1 H), 2.89 (m, 4 H), 2.72 (m, 2H), 2.40 (s, 3 H), 1.87 (dd, J=6.8, 14.1 Hz, 2 H), 1.63 (m, 3 H), 1.28 (d, J=6.8 Hz, 6 H).

Preparation 9 Synthesis of [(3R)-pyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate

Add phosene (1.14 mL, 20 mass % in toluene, 3.20 mmol) to a cold (0° C.) solution of tert-butyl (3R)-3-hydroxypyrrolidine-1-carboxylate (500 mg, 2.67 mmol) and TEA (0.37 mL, 2.6 mmol) in THF (13 mL). Remove the cold bath and stir the mixture at RT.

After 30 minutes, concentrate the mixture under reduced pressure and dissolve the residue in DCM (11 mL). Add this solution to a solution of 3-isopropyl-5-methyl-N-(4-piperidyl)pyrazolo[1,5-a]pyrimidin-7-amine (365 mg, 100 mass %, 0.365 g) and TEA (0.3 mL) in DCM (11 mL). Stir the mixture at RT. After 10 minutes, add saturated aqueous NaHCO₃ solution and extract with more DCM. Combine the organic layers and wash with saturated aqueous NaCl dry over magnesium sulfate, filter, and concentrate under reduced pressure to give a residue. Purify the residue by flash chromatography (silica gel), eluting with hexane: ethyl acetate to provide [(3R)-1-tert-butoxycarbonylpyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate (350 mg) as a yellowish oil. Mass spectrum (m/z): 487 (M+1).

Add dropwise trifluoroacetic acid (0.8 mL, 0.72 mmol) to a solution of [(3R)-1-tert-butoxycarbonylpyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate (350 mg, 0.72 mmol) in DCM (7 mL). Stir at RT. After 45 minutes, concentrate the mixture under reduced pressure. Purify the residue by SCX-2 cartridge elution with 10% DCM: MeOH then MeOH (2 N NH₃). Concentrate the basic fraction under reduced pressure to provide [(3R)-pyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate (246 mg) as a brownish solid. Mass spectrum (m/z): 387 (M+1).

Preparation 10 Synthesis of 3-isopropyl-5-methyl-4H-pyrazolo[1,5-a]pyrimidin-7-one

Dissolve 4-isopropyl-1H-pyrazol-5-amine (2.2 kg, 17.6 mol) and ethyl acetoacetate (2.86 kg, 1.25 eq.) into acetic acid (17.6 L, 8.0 mL/g.). Heat the mixture to 110-115° C. and then cool to 35-40° C. Add heptane and MTBE (44 L, 20 mL/g., 5/1 ratio). Filter and rinse the solid with—heptane (4.4 L, 2 mL/g.) to give the title compound (2.28 kg, 85.5% yield). ¹H NMR (500 MHz, DMSO) δ 11.81 (s, 1H), 7.77 (s, 1H), 5.50 (s, 1H), 3.08-3.05 (m, 1H), 2.31 (s, 3H), 1.22 (d, J=5.0 Hz, 6H).

Preparation 11 Synthesis of 7-chloro-3-isopropyl-5-methylpyrazolo[1,5-a]pyrimidine

Dissolve 3-isopropyl-5-methyl-4H-pyrazolo[1,5-a]pyrimidin-7-one (2.1 kg, 11.0 mol) and N,N-dimethylaniline (0.86 kg, 0.65 eq.) in ACN (8.4 L, 4 mL/g.). Heat the reaction to 50-55° C. and add POCl₃ (4.2 kg, 2.5 eq.) dropwise. Adjust temperature to 60-65° C. and stir mixture for 9 hours. Cool mixture to 25-30° C. and pour into 2M potassium phosphate buffer (pH=8.0, 42 L, 20 mL/g). Add MTBE (23.9 L, 11.4 mL/g) and extract the organic phase. Wash organic phase sequentially with 20% citric acid solution (4.2 L, 2.0 mL/g) twice, 10% aqueous solution of NaHCO₃ (10.5 L, 5.0 mL/g) and saturated aqueous NaCl (10.5 L, 5.0 mL/g). Dry the organic phase over Na₂SO₄, filter, and concentrate under reduced pressure to provide the title compound (1.8 kg, 78% yield). ¹H NMR (400 MHz, CDCl₃) δ 8.02 (s, 1H), 6.75 (s, 1H), 3.27-3.25 (m, 1H), 2.58 (s, 3H), 1.42 (d, J=8.0 Hz, 6H).

Preparation 12 3-isopropyl-5-methyl-N-(4-piperidyl)pyrazolo[1,5-a]pyrimidin-7-amine

Add 3-isopropyl-5-methyl-N-(4-piperidyl)pyrazolo[1,5-a]pyrimidin-7-amine dihydrochloride (2.2 kg, 6.4 mol) to 1 M aqueous solution of sodium hydroxide (19.2 L, 3.0 eq.) at 10-15° C. Stir the reaction mixture for 15-20 minutes then add 2-methyltetrahydrofuran (4.70 L, 10.0 equiv) and stir for 20-25 minutes. Separate the organic phase and wash the aqueous phase with 2-methyltetrahydrofuran (6.6 L, 3.0 mL/g, 3 times). Combine the organic solutions and wash with saturated aqueous NaCl (11 L, 5.0 mL/g). Dry the organic phase over Na₂SO₄, filter, and concentrate under reduced pressure. Add MTBE (6.6 L, 3.0 mL/g) and stir for 40 minutes at 25-30° C. Filtration affords the title compound (1.5 kg, 85.7% yield). ¹H NMR (400 MHz, CDCl₃) δ 7.81 (s, 1H), 6.10 (d, J=8.0 Hz 1H), 5.75 (s, 1H), 3.59-3.54 (m, 1 H), 3.32-3.28 (m, 1 H), 3.22-3.19 (m, 2 H), 2.77-2.73 (m, 2 H), 2.51 (s, 3H), 2.11 (d, J=8.0 Hz, 2H), 1.56-1.50 (m, 3 H), 1.34 (d, J=8.0 Hz, 6H).

Example 1 Synthesis of [(3S)-1-[(E)-4-(dimethylamino)but-2-enoyl]pyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate

[*Note that as shown here in Example 1, the chiral center has changed orientation and the S enantiomer form is represented differently than as shown above the examples in structure (II).] Add (E)-4-(dimethylamino)but-2-enoic acid hydrochloride (15.0 g, 90.3 mmol, 1.2 eq), N,N-diisopropylethylamine (31.3 mL, 23.4 g, 181 mmol, 2.4 eq), and HATU (42.9 g, 113 mmol, 1.5 eq) to a suspension of [(3S)-pyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate (29.1 g, 75.3 mmol) in THF (146 mL) at 23° C., and stir the mixture for 90 minutes. Dilute with phosphate buffer (0.5 M, pH=9, 150 mL), extract with DCM (2×375 mL), dry (MgSO₄), and concentrate in vacuo. Purify the resulting residue (ca. 95 g) by chromatography (load residue dissolved in 65 mL of DCM; 330 g of SiO₂; eluent: MTBE/7N NH₃ in MeOH 0% to 10%; TLC:MTBE/7N NH₃ in MeOH 5:1). Dissolve the material (ca. 40 g) in DCM (400 mL), wash with 1 M aq. K₂HPO₄ (1 M, 80 mL), dry (MgSO₄), and concentrate in vacuo. Purify the residue (ca. 38 g) by chromatography (load residue absorbed in SiO₂ (50 g); 330 g of SiO₂; eluent: MTBE/7N NH₃ in MeOH 0% to 10%) to obtain [(3S)-1-[(E)-4-(dimethylamino)but-2-enoyl]pyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate (28.1 g, 75%) as a white solid. ES/MS m/z 498 (M+H). ¹H NMR (CD₃OD) δ 1.33 (d, 6H), 1.64 (m, 2H), 2.10 (m, 2H), 2.18 (m, 1H), 2.26 (m, 1H), 2.29 (s, 6H), 2.50 (s, 3H), 3.11 (m, 2H), 3.18 (dd, 2H), 3.29 (dq, 1H), 3.70 (m, 3H), 3.87 (m, 2H), 4.14 (m, 2H), 5.31 (m, 1H), 6.12 (s, 1H), 6.47 (m, 1H), 6.86 (m, 1H), 7.88 (s, 1H). [α]_(D) ²⁰=+49.9° (C=2.0, MeOH). Enantiomeric excess (ee)=97%. Rt (retention time)=2.79 minutes (UV); LC Column: CHIRALPAK® AS (4.6×150 mm, 5 μm); MeOH+0.2% DMEA; Flow Rate: 1.0 mL/min.

Alternative Synthesis of [(3S)-1-[(E)-4-(dimethylamino)but-2-enoyl]pyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate

Add N,N-diisopropylethylamine (0.36 mL, 2.1 mmol,) to a solution of [(3S)-pyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate (170 mg, 0.4091 mmol), (E)-4-(dimethylamino)but-2-enoic acid; hydrochloride (135 mg, 0.81512 mmol) and HATU (317 mg, 0.8181 mmol) in N,N-dimethylformamide (4 mL). Stir at RT. After 5 minutes, concentrate the mixture under reduced pressure. Purify the residue by SCX-2 cartridge eluting with 10% DCM:MeOH then MeOH (2N NH₃). Concentrate the basic fraction under reduced pressure and purify the residue through ISCO™ reversed-phase Claricep C-series eluting with NH₄CO₃ pH 9/ACN to provide [(3S)-1-[(E)-4-(dimethylamino)but-2-enoyl]pyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate (129 mg, 0.255 mmol) as a white solid. Mass spectrum (m/z): 498 (M+1). ¹H NMR (400.13 MHz, MeOD): 7.88 (s, 1H), 6.85 (m, 1 H), 6.47 (m, 1 H), 6.12 (s, 1 H), 3.91-3.52 (m, 5 H), 3.13 (m, 1 H), 3.03 (m, 2 H), 2.94 (m, 1 H), 2.39 (s, 3 H), 2.15 (s, 6 H), 2.06 (m, 1 H), 1.88 (d, J=11.5 Hz, 2 H), 1.66 (m, 2 H), 1.28 (d, J=6.8 Hz, 6H).

Alternative Synthesis of [(3S)-1-[(E)-4-(dimethylamino)but-2-enoyl]pyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate

Dissolve [(3S)-pyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate (550 g, 1.4 mol) in THF (5.5 L, 10.0 mL/g) at 15-30° C. Add (E)-4-(dimethylamino)but-2-enoic acid hydrochloride (278 g, 1.2 eq.) and TEA (1.17 L, 6.0 eq.) at 15-30° C. and stir for 40 minutes. Add 50% propylphosphonic anhydride in EtOAc (1.68 L, 1.2 equiv) at 15-30° C. and stir for 12 hours. Filter and solvent exchange the filtrate with isopropyl acetate under reduced pressure. Add 2 M aqueous NaOH (2.75 L, 5 mL/g) and stir for 20 minutes at 25-30° C. Extract the organic phase and wash with saturated aqueous NaCl (2.75 L, 5 mL/g). Dry over Na₂SO₄, filter, and concentrate under reduced pressure. Add heptane (3.85 L, 7 mL/g) and THF (16.5 L, 3 mL/g) at 15-30° C. Stir for 1 hour and filter to afford the title compound (440 g, 63.2% yield). ¹H NMR (500 MHz, CD₃OD) δ 7.86 (s, 1H), 6.83 (d, J=10.7 Hz, 1H), 6.43 (dd, J=34.3, 14.9 Hz, 1H), 6.08 (s, 1H), 5.26 (d, J=24.2 Hz, 1H), 4.85 (s, 2H), 4.22-4.01 (m, 2H), 3.90-3.76 (m, 2H), 3.61-3.47 (m, 1H), 3.36-3.21 (m, 2H), 3.17-3.11 (m, 2H), 3.12-2.98 (m, 2H), 2.47 (s, 3H), 2.28-2.21 (m, 7H), 2.16-2.00 (m, 3H), 1.68-1.48 (m, 2H), 1.30 (d, J=6.2 Hz, 6H).

Example 2 Synthesis of [(3S)-1-[(E)-4-(dimethylamino)but-2-enoyl]pyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate hydrochloride

[*Note that as shown here in Example 2, the chiral center has changed orientation and the S enantiomer form is represented differently than as shown above the Examples in structure (II).] Add HCl (1 M in EtOAc (0.589 mL, 0.590 g, 0.589 mmol, 1.07 eq) to a solution of [(3S)-1-[(E)-4-(dimethylamino)but-2-enoyl]pyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate (0.283 g, 0.549 mmol) in acetone (5.5 mL) at 23° C., and stir the mixture for 5 hours. Concentrate in vacuo to obtain [(3S)-1-[(E)-4-(dimethylamino)but-2-enoyl]pyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate hydrochloride (0.244 g, 81%) as a white solid. ES/MS m/z 498 (M+H).

¹H NMR (CD₃OD) δ 1.34 (d, 6H), 1.66 (m, 2H), 2.11 (m, 2H), 2.20 (m, 1H), 2.30 (m, 1H), 2.54 (s, 3H), 2.90 (s, 6H), 3.12 (m, 2H), 3.28 (dq, 1H), 3.74 (m, 4H), 3.95 (dd, 2H), 4.16 (m, 2H), 4.63 (m, 1H), 5.32 (m, 1H), 6.22 (s, 1H), 6.78 (m, 2H), 7.94 (s, 1H).

Example 3 Synthesis of [(3R)-1-[(E)-4-(dimethylamino)but-2-enoyl]pyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate

[*Note that as shown here in Example 3, the chiral center has changed orientation and the R enantiomer form is represented differently than as shown above the Examples in structure (III).] Add N,N-diisopropylethylamine (0.4 mL, 2.0 mmol,) to a solution of [(3R)-pyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate (170 mg, 0.43 mmol), (E)-4-(dimethylamino)but-2-enoic acid; hydrochloride (150 mg, 0.90 mmol) and HATU (343 mg, 0.87 mmol) in DMF (4 mL). Stir at RT. After 5 minutes, concentrate the mixture under reduced pressure. Purify the residue by SCX-2 cartridge eluting with 10% DCM:MeOH then MeOH (2 N NH₃). Concentrate the basic fraction under reduced pressure and purify the residue through ISCO reversed-phase Claricep C-series eluting with NH₄CO₃ pH 9/ACN to provide [(3R)-1-[(E)-4-(dimethylamino)but-2-enoyl]pyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate (188 mg) as a white solid. Mass spectrum (m/z): 498 (M+1).

¹H NMR (400.21 MHz, DMSO): 7.86 (s, 1 H), 7.41 (m, 1 H), 6.63 (m, 1 H), 6.37 (m, 1 H), 6.13 (s, 1 H), 5.16 (m, 1H), 4.09-3.92 (m, 2H), 3.78 (m, 2 H), 3.56 (m, 2 H), 3.13 (m, 1 H), 3.03 (m, 2 H), 2.93 (m, 1 H), 2.39 (s, 3 H), 2.14 (s, 6 H), 2.06 (m, 1 H) 1.88 (m, 2 H), 1.60 (m, 2 H), 1.28 (d, J=6.8 Hz, 6 H).

Example 4 Synthesis of crystalline [(3S)-1-[(E)-4-(dimethylamino)but-2-enoyl]pyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate hemi-edisylate hydrate

[*Note that as shown here in Example 4, the chiral center has changed orientation and the S enantiomer form is represented differently than as shown above the Examples in structure (II).] Place 2.0 g of [(3S)-1-[(E)-4-(dimethylamino)but-2-enoyl]pyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate in 8 mL of acetone while magnetic stirring at room temperature. In a separate vial, dissolve 505 mg of 1,2-ethanedisulfonic acid hydrate in 6 mL of acetone. Add the acid solution to the freebase solution and mix at RT. Stir the sample so that mixing is thorough, adding additional solvent to thin the slurry if necessary. Slurry the suspension overnight at 50° C. After stirring overnight, cool the remaining thick slurry of white solid to 20° C. Isolate the solids by vacuum filtration on filter paper and dry the resulting cake of white solid in place on the filter (2.1 g, 88% yield).

Obtain the XRD patterns of the crystalline solid on a Bruker D4 Endeavor X-ray powder diffractometer, equipped with a CuKa source λ=1.54060 Å) and a Vantec detector, operating at 35 kV and 50 mA. Scan the sample between 4 and 40° in 2θ, with a step size of 0.008° in 2θand a scan rate of 0.5 seconds/step, and with 0.6 mm divergence, 5.28 fixed anti-scatter, and 9.5 mm detector slits. Pack the dry powder on a quartz sample holder and obtain a smooth surface using a glass slide. Collect the crystal form diffraction patterns at room temperature and relative humidity. It is well known in the crystallography art that, for any given crystal form, the relative intensities of the diffraction peaks may vary due to preferred orientation resulting from factors such as crystal morphology and habit. Where the effects of preferred orientation are present, peak intensities are altered, but the characteristic peak positions of the polymorph are unchanged. See, e.g. The United States Pharmacopeia #23, National Formulary #18, pages 1843-1844, 1995. Furthermore, it is also well known in the crystallography art that for any given crystal form the angular peak positions may vary slightly. For example, peak positions can shift due to a variation in the temperature or humidity at which a sample is analyzed, sample displacement, or the presence or absence of an internal standard. In the present case, a peak position variability of ±0.2 in 2θwill take into account these potential variations without hindering the unequivocal identification of the indicated crystal form. Confirmation of a crystal form may be made based on any unique combination of distinguishing peaks (in units of ° 2θ), typically the more prominent peaks. Adjust the crystal form diffraction patterns, collected at room temperature and relative humidity, based on NIST 675 standard peaks at 8.853 and 26.774 degrees 2-theta.

A prepared sample of the crystalline hemi-edisylate hydrate is characterized by an XRD pattern using CuKa radiation as having diffraction peaks (2-theta values) as described in the table below, and in particular having a peak at 18.5° in combination with one or more peaks selected from the group consisting of 21.5°, 16.7°, and 15.2°; with a tolerance for the diffraction angles of 0.2 degrees.

X-ray powder diffraction peaks of the crystalline hemi-edisylate hydrate

Crystalline Hemi-edisylate hydrate Relative Intensity Peak Angle (°2-Theta) +/− 0.2° (% of most intense peak) 1 7.0 14.90% 2 10.3 36.50% 3 12.6 14.50% 4 15.2 47.70% 5 16.7 58.40% 6 18.5 100.00% 7 19.8 16.10% 8 21.5 63.20% 9 23.2 17.50% 10 24.3 10.90%

Example 5 Synthesis of crystalline [(3S)-1-[(E)-4-(dimethylamino)but-2-enoyl]pyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate besylate

[*Note that as shown here in Example 5, the chiral center has changed orientation and the S enantiomer form is represented differently than as shown above the examples in structure (II).] Place 1998 mg of [(3S)-1-[(E)-4-(dimethylamino)but-2-enoyl]pyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate in 15 mL of acetone while stirring at 1000 rpm at RT. Add 650 mg of benzenesulfonic acid (dissolved in 5 mL of acetone). Stir the sample at 1000 rpm at RT for one hour, and after some time, the solution clouds, and a thick slurry of white solid results. Isolate the white solid by vacuum filtration on filter paper. Dry the sample in the vacuum oven for 1 hour at 70° C. (2.23 g, 85% yield).

Synthesis of crystalline [(3S)-1-[(E)-4-(dimethylamino)but-2-enoyl]pyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate besylate

Dissolve [(3S)-1-[(E)-4-(dimethylamino)but-2-enoyl]pyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate (440 g, 1.1 mol) in EtOAc (1.4 L) and acetone (357 mL) at 15-30° C. Heat to 50-55° C. Dissolve benzenesulfonic acid monohydrate (156 g, 0.89 eq.) in EtOAc (709 mL) and acetone (166 mL) and add to reaction mixture at 5-10 mL/minutes at 50-55° C. Stir for 1 hour. Cool to 15-30° C. and stir for 12 hours. Filter and dry wet cake under nitrogen to afford title compound (525 g 72.9% yield). 1H NMR (500 MHz, CD₃OD) δ 7.89 (s, 1H), 7.85-7.79 (m, 2H), 7.43-7.39 (m, 3H), 6.82-6.66 (m, 2H), 6.15 (s, 1H), 5.27 (d, J=21.5 Hz, 1H), 4.11 (d, J=32.9 Hz, 2H), 3.94-3.79 (m, 4H), 3.33-3.18 (m, 2H), 3.10-2.97 (m, 2H), 2.84 (s, 6H), 2.49 (s, 3H), 2.25-1.94 (m, 5H), 1.68-1.51 (m, 2H), 1.31 (d, J=6.8 Hz, 6H).

Obtain the XRD patterns of the crystalline solid essentially as described in Example 4. A prepared sample of the crystalline besylate is characterized by an XRD pattern using CuKa radiation as having diffraction peaks (2-theta values) as described in the table below, and in particular having a peak at 21.5° in combination with one or more peaks selected from the group consisting of 12.4°, 17.3°, and 15.8°; with a tolerance for the diffraction angles of 0.2 degrees.

X-ray powder diffraction peaks of the crystalline besylate

Crystalline Besylate Relative Intensity Peak Angle (°2-Theta) +/− 0.2° (% of most intense peak) 1 6.3 46.30% 2 9.5 26.30% 3 10.7 26.30% 4 12.4 98.70% 5 15.8 52.00% 6 16.5 45.20% 7 17.3 56.60% 8 21.5 100.00% 9 23.4 36.80% 10 24.9 32.10%

Example 6 Synthesis of crystalline [(3S)-1-[(E)-4-(dimethylamino)but-2-enoyl]pyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate hydrochloride

[*Note that as shown here in Example 6, the chiral center has changed orientation and the S enantiomer form is represented differently than as shown above the examples in structure (II).] Place 557 mg of [(3S)-1-[(E)-4-(dimethylamino)but-2-enoyl]pyrrolidin-3-yl] 4-[(3-isopropyl-5-methyl-pyrazolo[1,5-a]pyrimidin-7-yl)amino]piperidine-1-carboxylate in 4 mL of acetone while stirring at 1000 rpm at RT. Add 1200 μL of HCl (1M in ethyl acetate, 1.07 eq.). Stir the sample at 1000 rpm overnight to give a thick slurry of white solid. Isolate the white solid by vacuum filtration on filter paper. Dry the resulting cake of white solid in place on the filter under air stream for 10 minutes (385 mg, 64% yield).

Obtain the XRD patterns of the crystalline solid essentially as described in Example 4. A prepared sample of the crystalline hydrochloride hydrate is characterized by an XRD pattern using CuKa radiation as having diffraction peaks (2-theta values) as described in the table below, and in particular having a peak at 18.9° in combination with one or more peaks selected from the group consisting of 5.5°, 15.5°, and 9.7°; with a tolerance for the diffraction angles of 0.2 degrees.

X-ray powder diffraction peaks of the crystalline hydrochloride

Crystalline Hydrochloride Relative Intensity Peak Angle (°2-Theta) +/− 0.2° (% of most intense peak) 1 5.5 79.40% 2 6.2 54.40% 3 9.2 31.50% 4 9.7 56.10% 5 11.1 26.70% 6 14.2 29.80% 7 15.5 61.70% 8 18.9 100.00% 9 19.5 30.80% 10 23.4 40.40%

Biological Assays

The following assays demonstrate that a compound of the invention is an inhibitor of CDK7 activity. The results of the assays also show that a compound of the invention inhibits CDK7 signaling in the cancer cells. Additionally, a compound of the invention inhibits proliferation in cancer cell lines and tumor growth in xenograft tumor model of cancer.

“IC₅₀” refers to the concentration of an agent that produces 50% of the maximal inhibitory response possible for that agent or, alternatively, to the concentration of an agent which produces 50% displacement of ligand specific binding to the receptor; Relative IC₅₀ values are determined using fluorescence unit by calculating percent inhibition with respect to on-plate “MIN” and “MAX” controls and then fitting the ten-point dose response data to a four-parameter logistic equation.

CDK7 and CDK9 Kinase Activity Assays

The purpose of this assay is to measure the ability of a compound of the invention to inhibit CDK7/CyclinH/Mat1 complex kinase activity. To demonstrate whether compounds included within the present invention exhibit any affinity for CDK7, CDK7 and CDK9, the biochemical assays are performed with no preincubation of the enzyme with the compound or with 3 hours preincubation. Functional assays provide support on whether the compounds of the present invention exhibit the ability to inhibit the CDK7 and CDK9 kinase activities. All ligands, solvents, and reagents employed in the following assays are readily available from commercial sources, or can be readily synthesized by one skilled in the art. The IC₅₀ determination for CDK7 and CDK9 are determined as follows.

Biochemical Assay for Inhibition of CDK7/CyclinH/MAT1

The IC₅₀ activity of the inhibitor is determined using radiolabel filter binding (FB) assays using the purified human recombinant enzyme in the presence of ATP//[³³P]ATP and peptide substrate. The ATP concentrations chosen are at or near the enzyme Km for ATP.

Reactions are carried out in 96 well polystyrene plates in a final volume of 25 μL per well. 5 μL of test compound in 20% DMSO, 10 μL of substrate solution (ATP/33PATP and CDK7/9 tide) and 10 μL of enzyme solution are mixed. The substrate solution is prepared to give a final concentration of 100 μM ATP/[³³P]ATP (NEN 10 μCi/μL, 3000 Ci/mmol) and 250 μM CDK7/9 peptide ((YSPTSPSYSPTSPSYSPTSPSKKKK) (SEQ ID NO: 1)) diluted in kinase buffer of 4 mM MgCl₂, 0.01% TRITON™ X-100, 2 mM DTT and 20 mM HEPES. The enzyme solution is prepared for a final concentration of 1 nM CDK7/CyclinH/Mat1 enzyme [Proqinase 0366-0360-4 Lot 002)] diluted in kinase buffer. Test compounds are serially diluted 1:3 in 20% DMSO to create a 10 point curve at a starting concentration of 20 μM. 20% DMSO buffer alone without test compound is employed as high control (full activity in the absence of any inhibitor), 500 mM EDTA is used to determine the level of background in the absence of enzyme activity (low control). After mixing 5 μL of compounds with 10 μL of enzyme solution the plate is incubated for 0 or 180 minutes at 22° C. After that time the reaction is initiated by the addition of 10 μL substrate solution and incubated for 50 minutes at 22° C. The reaction is terminated by the addition of 80 μL of cold 10% ortophosphoric solution. The Filter Plates (opaque, non-sterile filter plates) are prewashed with 10 μL of 10% orthophosphoric solution to each well. 100 μL of the mixture are transferred to a phosphocellulose filter and incubated at room temperature for 45 minutes. Filter plates are washed with 200 μL 0.5% orthophosphoric acid 3 times on a filter plate processor. Incorporation of 33Pi (counting of “cpm”) is determined by adding 80 μL of MICROSCINT™ to each well and read on a counter after an hour. Data is processed through a GENEDATA SCREENER® tool. Data are analyzed using a 4-parameter nonlinear logistic equation (four-parameter logistic concentration-response curve): Y=bot+[(top−bot)/1+(x/IC₅₀)slope] where Y=% inhibition, X=concentration yielding y % inhibition, Bottom=minimum value of y attained by curve, Top=maximum value of y attained by curve and Slope=steepness of curve at IC₅₀. % Inh=[(median Max−x/median Max−median Min)]·100IC₅₀: concentration of compound that reduces a given response (ligand binding, enzyme response) by 50%.

The compounds described in Examples 1 and 3 display an IC₅₀ of 0.0173 μM and 0.0487 μM in CDK7 without preincubation, respectively. After 3 hours of preincubation of CDK7 enzyme with Examples 1 and 3, they show an IC₅₀ of 0.00237 μM and 0.00506 μM, respectively. These data show that both Examples 1 and 3 inhibit CDK7.

Assay for Inhibition of CDK9/CyclinT1 Kinase Activity

The IC₅₀ activity of the inhibitor is determined using radiolabel filter binding (FB) assays using the purified human recombinant enzyme in the presence of ATP and peptide substrate. The ATP concentrations chosen are at or near the enzyme Km for ATP. Reactions are carried out in 96 well polystyrene plates in a final volume of 25 μL per well. 5 μL of test compound in 20% DMSO, 10 μL of substrate solution (ATP//[³³P]ATP and CDK7/9 tide) and 10 μL of enzyme solution are mixed. The substrate solution is prepared to give a final concentration of 100 μM ATP/[³³P]ATP (NEN 10 uCi/μL, 3000 Ci/mmol) and 200 μM CDK7/9 peptide ((YSPTSPSYSPTSPSYSPTSPSKKKK) (SEQ ID NO: 1)) diluted in kinase buffer of 4 mM MgCl₂, 0.0025% TRITON™ X-100, 1.58 mM DTT and 15.80 mM HEPES. The enzyme solution is prepared for a final concentration of 7.5 nM CDK9/cyclinT1 enzyme [Proqinase 0371-0345-1 (Lot 004)] diluted in kinase buffer. Test compounds are serially diluted 1:3 in 20% DMSO to create a 10 point curve at a starting concentration of 20 μM. 20% DMSO buffer alone without test compound is employed as high control (full activity in the absence of any inhibitor), 500 mM EDTA is used to determine the level of background in the absence of enzyme activity (low control). After mixing 5 μL of compounds with 10 μL of enzyme solution the plate is incubated for 0 or 180 minutes at 22° C. After that time the reaction is initiated by the addition of 10 μL substrate solution and incubated for 60 minutes at 22° C. The reaction is terminated by the addition of 80 μL of cold 10% ortophosphoric solution. Filter plates (opaque, non-sterile filter plates) are prewashed with 10 μL of 10% orthophosphoric solution per well. 100 μL of the mixture are transferred to a phosphocellulose filter and incubate at room temperature for 45 minutes. Filter plates are washed with 200 μL 0.5% orthophosphoric acid 3 times on a filter plate processor. 80 μL of MICROSCINT™ is added to each well and read on a scintillation counter after an hour. Data is processed through a GENEDATA-SCREENER® tool. Data is analyzed using a 4-parameter nonlinear logistic equation (four-parameter logistic concentration-response curve): Y=bot+[(top-bot)/1+(x/IC₅₀)slope] where Y=% inhibition, X=concentration yielding y % inhibition, Bottom=minimum value of y attained by curve, Top=maximum value of y attained by curve and Slope=steepness of curve at IC₅₀. % Inh=[(median Max−x/median Max−median Min)]·100 IC₅₀: concentration of compound that reduces a given response (ligand binding, enzyme response) by 50%. IC₅₀ relative: concentration giving half the compound's maximum response.

The compounds described in Examples 1 and 3 display an IC₅₀ of 5.93 μM and 2.45 μM for CDK9 (3 hours preincubation), respectively. These data show that Examples 1 and 3 do not potently inhibit CDK9 activity.

Taken together, the data from the assays above demonstrate that the compounds of Examples 1 and 3 selectively inhibit CDK7 over CDK9.

CDK7 and CDK9 Cell Mechanistic Assays

The purpose of these assays is to measure the ability of compounds to inhibit CDK7 and CDK9 signaling in cancer cells in vitro.

Phospho-Carboxyl Terminal Domain (Rbp2) (Ser2) p-CTD (S2) Cell based Acumen Assay

HCT116 cells (ATCC CCL-247) are cultured in McCoy's 5A Medium Modified media supplemented with 10% FBS, 1% NaPyr and 1% Pen/Strep and plated (prior to becoming 70% confluent) in 96-well flat-bottom plates at a density of 5,000 cells per well in 100 μL volume. The cells are then incubated overnight in a cell culture incubator (5% CO₂, 95% Relative Humidity (RH) and 37° C.) and allowed to attach to the plate. The following morning the cells are dosed with compounds. Compound inhibitors are first solubilized at 60 μM in culture medium containing 0.6% DMSO. Subsequently compound serial dilutions (1:3) are prepared over a 60 μM to 0.003 μM range. Cells are dosed with the addition of 50 μL from serial dilution plate to assay plate containing cells attached with 100 μL of media producing a final DMSO concentration of 0.2% with a final compound concentration dose range between 20 and 0.001 μM. For max point media containing 0.2% of DMSO is used and for min point, a reference compound diluted at 0.83 μM final concentration in the growth media containing 0.2% DMSO is used. After dosing with compounds the cell plates are incubated at 37° C. and 5% CO₂ for 4 hours. The growth media is removed carefully and the cells are fixed by adding 100 μL of 4% para-formaldehyde for 30 minutes at RT. Cells are washed once with PBS and incubated with 100 μL of cold MeOH for 15 minutes at RT for cell permeation. Cells are washed twice with PBS (100 μL/each) and blocked with 100 μL/well of 1% BSA/PBS for 30 minutes at RT. 50 μL of 1:1000 primary antibody (Anti-phospho CTD Ser2 Abcam, cat# ab5095-100) dilution in 1% BSA/PBS are added per well, the plates are sealed and incubated overnight at 4° C.

The following day cells are washed three times with PBS (100 μL/well) and incubated with 50 μL/well of secondary antibody (1:2000 dilution, Goat anti-rabbit IgM ALEXA FLUOR™ 488) in PBS for 1 hour at RT. After washing 3× with PBS (100 μL/well), 100 μL of 50 μg/mL RNAase and 1:1000 propidium iodide dilution in PBS are added per well. Plates are sealed and incubated 1 hour at RT on the bench (preserved from light). Plates are analyzed on Acumen on FL2 (mean intensity), and FL3 (total intensity). Fluorescence plates are scanned with ACUMEN EXPLORER™ [Laser-scanning fluorescence microplate cytometer manufactured by TTP LABTECH LTD] to measure anti-phospho-carboxyl terminal domain at Serine 2 (pCTD). Image analysis is based on cellular fluorescent signals for identifying positive cells. pCTD (S2) positive cells are identified by mean intensity at 500-530 above the threshold. Total intensity at 575-640 from propidium iodide/DNA is used to identify individual cells. Assay output is % pCTD positive cells.

The IC₅₀ is determined by curve fitting to a four parameter logistic for each output using GENE DATA™. The compounds described in Examples 1 and 3 display a relative IC₅₀>20 μM and 3.52 μM for phosphoCTD (S2), respectively. These data show that both Examples 1 and 3 do not potently inhibit CDK9 in the cells.

Phospho-Carboxyl Terminal Domain (Rbp2) (Ser5) p-CTD (S5) Cell Based Acumen Assay

HCT116 cells (ATCC CCL-247) are cultured in McCoy's 5A Medium Modified media supplemented with 10% FBS, 1% NaPyr and 1% Pen/Strep and plated (prior to becoming 70% confluent) in 96-well flat-bottom plates at a density of 5,000 cells per well in 100 μL volume. The cells are incubated overnight in a cell culture incubator (5% CO₂, 95% Relative Humidity (RH) and 37° C.) and allowed to attach to the plate. The following morning, the cells are dosed with compounds. Compound inhibitors are solubilized at 60 μM in culture medium containing 0.6% DMSO. Subsequently compound serial dilutions (1:3) are prepared over a 60 μM to 0.003 μM range. Cells are dosed with the addition of 50 μL from serial dilution plate to assay plate containing cell attached with 100 μL of media producing a final DMSO concentration of 0.2% with a final compound concentration dose range between 20 and 0.001 μM. For max point media containing 0.2% of DMSO is used and for min point, a reference compound diluted at 0.83 μM final concentration in the growth media containing 0.2% DMSO is used. After dosing with compounds the cell plates are incubated at 37° C. and 5% CO₂ for 4 hours. Growth media is removed carefully and the cells are fixed by adding 100 μL of 4% para-formaldehyde for 30 minutes at RT. Cell are washed once with PBS and incubated with 100 μL of cold MeOH for 15 minutes at RT for cell permeation. Again cells are washed twice with PBS (100 μL/each) and blocked with 100 μL/well of 1% BSA/PBS for 30 min at RT. 50 μL of 1:1000 primary antibody (Anti-phosphoCTD Ser5 Bethyl Laboratories cat# A300-655A) dilution in 1% BSA/PBS are added per well, the plates are sealed and incubated overnight at 4° C.

The following day cells are washed three times with PBS (100 μL/well) and incubated with 50 μL/well of secondary antibody (1:2000 dilution, Goat anti-rabbit IgM ALEXA FLUOR™ 488) in PBS for 1 hour at room temperature. After washing 3× with PBS (100 μL/well), 100 μL of 50 μg/mL RNAase (Sigma) and 1:1000 propidium iodide dilution in PBS are added per well. Plates are sealed and incubated for 1 hour at RT on the bench (preserved from light). Plates are analyzed on Acumen on FL2 (mean intensity), and FL3 (total intensity). Fluorescence plates are scanned with ACUMEN EXPLORER™ [Laser-scanning fluorescence microplate cytometer manufactured by TTP LABTECH LTD] to measure anti-phospho-carboxyl terminal domain at Serine 5 (pCTD). Image analysis is based on cellular fluorescent signals for identifying positive cells. pCTD (S5) positive cells are identified by mean intensity at 500-530 above the threshold. Total intensity at 575-640 from propidium iodide/DNA is used to identify individual cells. Assay output is % pCTD positive cells. The IC₅₀ is determined by curve fitting to a four parameter logistic for each output using GENE DATA™.

The compounds described in Examples 1 and 3 display a Relative IC₅₀ of 0.148 μM and 0.198 μM for pCTD Ser5, respectively. These data show that both Examples 1 and 3 inhibit CDK7 cellular activity.

cMyc Cell Based Acumen Assay

HCT116 cells (ATCC CCL-247) are cultured in McCoy's 5A Medium Modified media supplemented with 10% FBS, 1% NaPyr and 1% Pen/Strep and plated (prior to becoming 70% confluent) in 96-well flat-bottom plates at a density of 5,000 cells per well in 100 μL volume. The cells are then incubated overnight in a cell culture incubator (5% CO₂, 95% Relative Humidity (RH) and 37° C.) and allowed to attach to the plate. The following morning the cells are dosed with compounds. Compound inhibitors are solubilized at 60 μM in culture medium containing 0.6% DMSO. Subsequently compound serial dilutions (1:3) are prepared over a 60 μM to 0.003 μM range. Cells are dosed with the addition of 50 μL from serial dilution plate to assay plate containing cell attached with 100 μL of media producing a final DMSO concentration of 0.2% with a final compound concentration dose range between 20 μM and 0.001 μM. For max point media containing 0.2% of DMSO is used and for min point, a reference compound diluted at 0.83 μM final concentration in the growth media containing 0.2% DMSO is used. After dosing with compounds the cell plates are incubated at 37° C. and 5% CO₂ for 4 hours. Growth media is removed carefully and the cells are fixed by adding 100 μL of 4% para-formaldehyde for 30 minutes at RT. Cell are washed once with PBS and incubated with 100 μL of cold MeOH for 15 minutes at RT for cell permeation. Again cell are washed twice with PBS (100 μL/each) and blocked with 100 μL/well of 1% BSA/PBS for 30 minutes at RT. 50 μL of 1:1000 primary antibody (Anti-c-Myc antibody [Y69] Abcam cat# ab32072) dilution in 1% BSA/PBS are added per well, the plates sealed and incubated overnight at 4° C. The following day cells are washed three times with PBS (100 μL/well) and incubated with 50 μL/well of secondary antibody (1:2000 dilution, Goat anti-rabbit IgM ALEXA FLUOR™ 488) in PBS for 1 hour at RT. After wash 3× with PBS (100 μL/well), 100 μL of 50 μg/mL RNAase and 1:1000 propidium iodide (Invitrogene) dilution in PBS are added per well. Plates are sealed and incubated for 1 hour at RT on the bench (preserved from light). Plates are analyzed on Acumen on FL2 (mean intensity), and FL3 (total intensity). Fluorescence Plates are scanned with ACUMEN EXPLORER™ [Laser-scanning fluorescence microplate cytometer manufactured by TTP LABTECH LTD] to measure anti-phospho-carboxyl terminal domain at Serine 5 (pCTD). Image analysis is based on cellular fluorescent signals for identifying positive cells. pCTD (S5) positive cells are identified by mean intensity at 500-530 above the threshold. Total intensity at 575-640 from propidium iodide/DNA is used to identify individual cells. Assay output is % pCTD positive cells. The IC₅₀ is determined by curve fitting to a four parameter logistic for each output using GENE DATA™.

The compounds described in Examples 1 and 3 display a Relative IC₅₀ of 0.0828 μM and 0.0573 μM for cMyc. These data show that both Examples 1 and 3 inhibit the transcription of cMyc in HCT116 cells.

Selectivity Profiling Experiment: Proqinase WT Profiler

Kinase inhibition profile of compound is determined by measuring residual activity values at four concentrations in singlicate in 320 wild-type protein kinase assays. The compounds are tested at 20 μM, 2 μM, 0.2 μM and 0.02 μM in singlicate. The final DMSO concentration in all reaction cocktails (including high and low controls) is 1%.

Protein Kinase Assay

A radiometric protein kinase assay (33PANQINASE® Activity Assay, ProQinase) is used for measuring the kinase activity of the 320 protein kinases. All kinase assays are performed in 96-well FLASHPLATES' in a 50 μL reaction volume. The reaction cocktail is pipetted in 4 steps in the following order:

-   -   1. 10 μL of non-radioactive ATP solution (in H₂O)     -   2. 25 μL of assay buffer/[γ-33P]-ATP mixture     -   3. 5 μL of test sample in 10% DMSO     -   4. 10 μL of enzyme/substrate mixture

The assay for all protein kinases contain 70 mM HEPES-NaOH pH 7.5, 3 mM MgCl₂, 3 mM MnCl₂, 3 μM Na-orthovanadate, 1.2 mM DTT, ATP (variable amounts, corresponding to the apparent ATP-Km of the respective kinase, see Table 1), [γ-33P]-ATP (approx. 8×1005 cpm per well), protein kinase (variable amounts; see Table 1), and substrate (variable amounts; see Table 1). All PKC assays (except the PKC-mu and the PKC-nu assay) additionally contain 1 mM CaCl₂, 4 mM EDTA, 5 μg/mL Phosphatidylserine and 1 μg/mL 1,2-Dioleyl-glycerol. The CAMK1D, CAMK2A, CAMK2B, CAMK2D, CAMK2G, CAMK4, CAMKK1, CAMKK2, DAPK2, EEF2K, MYLK, MYLK2 and MYLK3 assays additionally contain 1 μg/mL Calmodulin and 0.5 mM CaCl₂). The PRKG1 and PRKG2 assays additionally contain 1 μM cGMP. The DNA-PK assay additionally contained 2.5 μg/mL DNA.

The protein kinase reaction cocktails are incubated at 30° C. for 60 minutes. The reaction is stopped with 50 μL of 2% (v/v) H₃PO₄, plates are aspirated and washed two times with 200 μL 0.9% (w/v) NaCl. Incorporation of 33Pi (counting of “cpm”) is determined with a microplate scintillation counter. All protein kinase assays are performed with a BeckmanCoulter BIOMEK® 2000/SL robotic system. All protein kinases provided by ProQinase are expressed in Sf9 insect cells or in E. coli as recombinant GST-fusion proteins or His-tagged proteins, either as full-length or enzymatically active fragments. All kinases are produced from human cDNAs and purified by either GSH-affinity chromatography or immobilized metal. Affinity tags are removed from a number of kinases during purification. The purity of the protein kinases is examined by SDS-PAGE/Coomassie staining, the identity is checked by mass spectroscopy. Kinases from external vendors (CAR=Carna Biosciences Inc.; INV=Life Technologies (Invitrogen Corporation™); MIL=Merck-Millipore (Millipore Corporation™), see Table 1) are expressed, purified and quality-controlled by virtue of the vendors readings. The concentrations of enzymes and substrates for the assays are shown in Table 1.

Evaluation of Raw Data

For each kinase, the median value of the cpm of three wells is defined as “low control” (n=3). This value reflects unspecific binding of radioactivity to the plate in the absence of a protein kinase but in the presence of the substrate. Additionally, for each kinase the median value of the cpm of three other wells is taken as the “high control”, i.e. full activity in the absence of any inhibitor (n=3). The difference between high and low control of each enzyme is taken as 100% activity. As part of the data evaluation, the low control of each kinase is subtracted from the high control value as well as from their corresponding “compound values”. The residual activity (in %) for each compound well is calculated by using the following formula: Res. Activity (%)=100×[(signal of compound−low control)/(high control−low control)]. Non Standard IC₅₀s are calculated using a customized excel spreadsheet in conjunction with XLFit Add-in. Due to the low number of data points, (4) XL-Fit calculates a non standard IC₅₀ using a four parametric equation where three parameters are locked to fixed values.

Equation is: Y=B+((A−B))/

1+(x/C)

{circumflex over ( )}D A: Minimum value of activity, Also known as Bottom. Fixed to 0 B: Maximum value of activity, Also known as Top. Fixed to 100 C: Inflexion point of the curve D: Hill Slope. Fixed to 1 Y: The dependent variable (i.e. what you measure as the signal) X: The independent variable (i.e. what you control, such as, dose, concentration, etc.)

The way to calculate the Non Standard IC₅₀ is to assign random values to C parameter and repeat it iteratively. The algorithm then measures the differences in the sum of the residuals squared and will look for successive consecutive iterations where the change in the residuals is converging. Once the convergence limit has been met, the solution is regarded as the optimum and the fitting process ends.

CDK12 and CDK13 (ProQinase) are tested essentially as above but separately at 10 concentrations (2×10⁵ M to 6×10¹⁰ M) using semi-logarithmic dilutions. For the 10 points, the anaylsis the residual activities for each concentration and the compound IC₅₀ values are calculated using QUATTRO® WORKFLOW™ V3.1.1. The fitting model for the IC₅₀ determinations was “Sigmoidal response (variable slope)” with parameters “top” fixed at 100% and “bottom” at 0%. The fitting method used was a least-squares fit. Data are shown in Table 1 below.

TABLE 1 Kinase ATP Kinase Kinase Conc. Conc. Substrate Substrate IC₅₀ Name Family nM μM Name μg/50 μL μM CDK7/CycH/MAT1 CMGC 3.3 3 RBER- 2 0.0928 CHKtide CDK9/CycT1 CMGC 2.2 1 RBER- 2 6.32 CHKtide CDK1/CycB1 CMGC 7 1 RBER- 2 20.000 CHKtide CDK2/CycE1 CMGC 1.5 1 RBER- 1 20.000 CHKtide CDK4/CycD1 CMGC 3.3 3 RBER- 2 2.830 CHKtide CDK6/CycD1 CMGC 3.2 3 RBER- 2 8.079 CHKtide CDK8/CycC CMGC 8.3 1 RBER- 1 10.922 IRStide CDK16/CycY CMGC 3.2 0.3 GSK3(14- 2 9.073 27) CDK19/CycC CMGC 30.9 3 RBER- 2 7.414 IRStide CDK12/CycK CMGC 14.7 0.3 RBER- 2 14.780 IRStide CDK13/CycK CMGC 29.2 0.3 RBER- 1 20.000 CDC25tide

These data show that the compound of Example 1 is very selective for CDK7 from a representative panel of kinases.

Cell Proliferation Assay

The data in Table 2 shows that the compound of Example 1 inhibits proliferation and viability of the specified tumor cells lines. Cell lines are plated at the density 5000 cells per well in 100 μL per well growth medium into a white 96-well cell culture plate. See Table 2 for cell line and culture medium information. Plates are incubated at 37° C. and 5% CO₂. The following day, a serial dilution of the test compound is prepared by diluting the compound 1:3 in DMSO for 10 points. The DMSO plate is 1000× the final concentration. In addition to the CDK7 inhibitor, a DMSO alone column is included as a maximum growth control and 10 μM staurosporine final column is included as a maximum growth inhibition control. A 10× dilution plate is then prepared by adding 2 μL per well from the 1000×DMSO plate to 198 μL per well of OMEM (Life Technologies, Carlsbad, Calif., cat#31985-070). Cells are treated with indicated compound by adding 11 μL per well from the 10×OMEM plate to the cell plate containing 100 μL per well growth medium for a 1× final concentration. Plates are placed back into the incubator at 37° C. and 5% CO₂. Seven days after compound addition, plates are removed from the incubator and allowed to equilibrate to RT. CELL TITER GLO® reagent is thawed at room temperature and then prepare by mixing one vial of assay buffer with one vial of substrate and swirl gently to mix. CELL TITER GLO® reagent is then added to the cell plate, 100 μL per well, and place on a Titer Plate Shaker at speed setting 2 for 15 minutes at room temperature. After 15 minute incubation on shaker, luminescence is read, 1 second per well, using a Wallac VICTOR2™. Nonlinear regression and sigmoidal dose-response curves are used to calculate the half maximal inhibitory concentration (IC₅₀) with Graphpad Prism 6 software.

TABLE 2 Catalog Cell Line Histology IC₅₀ (μM) Number Media Information HCT116 Colorectal 0.04601 ATCC# CCL- McCoy's 5A (Gibco 16600) + Cancer 247 10% FBS (Hyclone SH30071.03) MCF7 Breast 0.03201 ATCC# HTB- RPMI 1640 with L- Cancer 22 Glutamine (Gibco 11875) + 10% FBS (Hyclone SH30071.03) HCC1806 Breast 0.02553 ATCC# CRL- RPMI 1640 with HEPES & Cancer 2335 L-Glutamine (Gibco 22400) + 10% FBS (Gibco cat#10082) NCI- Lung 0.0479 ATCC# HTB- RPMI 1640 with HEPES & H460 Cancer 177 L-Glutamine (Gibco 22400) + 10% FBS (Gibco cat#10082) NCI- Lung 0.01419 ATCC# HTB- RPMI 1640 with HEPES & H446 Cancer 171 L-Glutamine (Gibco 22400) + 1 mM Sodium Pyruvate (Gibco 11360) + 10% FBS (Hyclone SH30071.03) A2780 Ovarian 0.02651 ATCC# CRL- RPMI 1640 with L- Cancer 2772 Glutamine (Gibco 11875) + 10% FBS (Hyclone SH30071.03) SNU-16 Gastric 0.02312 ATCC# CRL- RPMI 1640 with HEPES & Cancer 5974 L-Glutamine (Gibco 22400) + 1 mM Sodium Pyruvate (Gibco 11360) + 10%FBS (Hyclone SH30071.03)

These data show that the compound of Example I inhibits the in vitro growth of cancer cell lines from a variety of histologies including colon, breast, lung, ovary and stomach, in a dose dependent manner.

Xenograft Tumor Model

The purpose of this assay is to measure reduction in tumor volume in response to the compound of Example 1. To evaluate in vivo efficacy of a test compound, multiple xenograft tumor models are utilized. Briefly, 5-10×10⁶ tumor cells in a 1:1 MATRIGEL® mix (0.2 mL total volume) are injected subcutaneously into the female athymic nude mice (Envigo, Harlan laboratories) for a majority of xenograft tumor models. Alternate mice strains are utilized to establish MDAMB468 (NOD SCID Gamma, Jackson labs), CT26 and EMT6 (BALB/c, Envigo, Harlan Laboratories) xenografts. After allowing tumors to reach a desired size of ˜300-500 mm³, animals are randomized into groups of 6-8 for efficacy studies. Test compound is administered via oral gavage (PO) at indicated doses and regimens. Tumor growth and body weight are monitored over time to evaluate efficacy and signs of toxicity.

Test compound is formulated in 5% N-methyl-2-pyrrolidone (NMP) in 1% hydroxyethylcellulose, 0.25% polysorbate 80, 0.05% antifoam in purified water (HEC) and administered by oral gavage (final volume 0.2 mL) at the doses indicated in Table 4. A test compound is formulated on a weekly basis and stored at 4° C. Vehicles are administered to the control groups according the schedules used above using a volume of 0.2 mL per dose. Mice are dosed via oral gavage and tumor samples are collected at termination and stored at −80° C.

Tumor size and body weight are recorded and analyzed bi-weekly. Blood is collected using DBS (dried blood spot) card 2 hours after dose and at termination. Tumors are collected at study termination, cut into 3 sections and either snap frozen for exposure and protein analysis, or placed in RNAlater® for RNA analysis. Tissue samples are frozen and stored at −80° C.

The compound of Example 1 demonstrates significant anti-tumor activity in human cancer xenograft models (Table 3).

TABLE 3 Summary of Example 1 in-vivo single-agent efficacy (ΔT/C) across variety of xenografts tumor models tested at different dose levels as indicated. Model Histology Mutations Example 1 Dose (mg/kg) Schedule Avg. ΔT/C A2780 Ovary ARID1A 20 QDx35 −41 COLO205 Ovary 20 QDx28 −4 CT26 Colorectal 20 QDx24 52 EMT6 Breast 20 QDx28 17 H441 Lung 20 QDx35 0 H460 Lung ARID1A 20 QDx35 16 HCC1806 Breast KMT2C 20 QDx28 −87 HCT116 Colorectal KMT2C 25 QDx21 −17 MDAMB468 Breast ARID1A, RB1 20 QDx28 −91 MIAPACA2 Pancreatic ARID1A 20 QDx35 10 MKN45 Stomach KMT2C 20 QDx35 57 MDAMB231 Breast 20 QDx35 −25 Delta T/C % is calculated when the endpoint tumor volume in a treated group is at or above baseline tumor volume. The formula is 100*(T−T0)/(C−C0). Here, T and C are mean endpoint tumor volumes in the treated or control group, respectively. T0 and C0 are mean baseline tumor volumes in those groups. *: Significant (p<0.05)

Biomarker Study

The purpose of this study is to evaluate potential predictive biomarkers for the compounds of the present invention.

Cancer cell lines are profiled to evaluate the anti-proliferative activity of a test compound in-vitro. Mutation, copy number and gene expression information of ARID1A, KMT2C, KMT2D and/or RB1 genes across cancer cell lines is obtained from COSMIC database (cancer.sanger.ac.uk) and cBioportal (http://www.cbioportal.org/). Cells are cultured in growth medium and plated into a 96-well plate in 100 μL/well growth medium at 5000 cells/well then incubated at 37° C., 5% CO₂ overnight. Cells are cultured using supplier recommended media and conditions well known in the art, for example with RPMI 1640 with or without HEPES & L-Glutamine (Thermo SH30255.01) and 1 mM Sodium Pyruvate, and 10% FBS (Gibco cat#10082). The 1000× intermediate dilution plate is prepared by making a 10 mM working solution of a test sample in DMSO and performing 1:3 dilutions in DMSO for 10 points. The 10× dosing plate is prepared by adding 2 μL from the 1000× intermediate dilution plate to 198 μL of OPTIMEM®+10% FBS and mixing well. The cell plate is then treated by adding 11 μL from the 10× dosing plate into the 100 μL/well cell plate for a 1× final concentration. Staurosporine is used as a maximum growth inhibition control at a final concentration of 5 μM. The cell plate is incubated for 7 days at 37° C., 5% CO₂. Seven days after treatment, Cell Titer-Glo® (Promega cat# G7571) assay buffer and substrate are removed from −20° C. and allowed to equilibrate to RT. Assay buffer is added to the substrate and swirled gently to mix. The CELL TITER-GLO® reagent (100 μL/well) is added to the cell plate and incubated at RT for 15 minutes. After 15 minutes, luminescence is read using a plate reader. Data is analyzed in Excel and graphed in GraphPad Prism. Statistical analysis and p value is calculated using Mann-Whitney nonparameteric t tests using GraphPad Prism.

A summary of proliferation data is shown in Table 4. Anti-proliferative effects of a test compound are categorized as insensitive (IC₅₀≥1 μM), cytostatic (IC₅₀<1 μM and % inhibition <70%) or cytotoxic (IC₅₀<1 μM and % inhibition ≥70%). Cell lines carrying inactivating or loss of function (LOF) mutations in either ARID1A, KMT2C, KMT2D or RB1 gene demonstrated significantly greater cytotoxic response to Example 1 compared to the rest of the cell lines in the panel (Table 5). In contrast, non-LOF cell lines demonstrated a higher (%) of cytostatic response in response to Example 1.

Furthermore, a number of xenograft tumor models carrying these mutations were utilized to evaluate the efficacy of Example 1 as a monotherapy (Table 3).

A summary of efficacy studies and anti-tumor activity (AT/C) is shown in Table 3. Example 1 demonstrated robust efficacy in a variety of tumor models, with significant regressions noted in the tumor models harboring mutations in ARID1A, KMT2C or RB1 genes. Taken together, these findings show that inactivating mutations in the ARID1A, KMT2C, KMT2D or RB1 gene presents a potential patient selection strategy for treatment with Example 1 across multiple cancer types.

TABLE 4 Summary of Example 1 anti-proliferative log-GI₅₀ (nM) and Growth-Inhibition (%) across variety of cancer cell lines as indicated. Cell lines treated for 7 days and analyzed using CellTiter-Glo ® assay. Anti-proliferation effect Media IC₅₀ % LOF Mutations in Gene(s) Cell Line Information Histology (μM) Inh. Outcome ARID1A KMT2C KMT2D RB1 22RV1 A PROSTATE 0.028 77 Cytotoxic Yes A2058 B SKIN 0.030 97 Cytotoxic Yes A2780 C OVARY 0.052 74 Cytotoxic Yes A375 B SKIN 0.055 86 Cytotoxic A549 D LUNG 0.139 64 Cytostatic A673 B BONE 0.014 96 Cytotoxic AN3CA E ENDOMETRIUM 0.050 67 Cytostatic Yes AZ521 F STOMACH 0.036 76 Cytotoxic BT20 B BREAST 0.373 45 Cytostatic C33A F ENDOMETRIUM 0.014 79 Cytotoxic Yes Yes CACO2 B INTESTINE 0.189 60 Cytostatic CAOV3 B OVARY 0.019 96 Cytotoxic Yes Yes CCRFCEM C BLOOD 0.040 96 Cytotoxic COLO201 C INTESTINE 0.123 61 Cytostatic COLO320 C + 0.8 ug/mL INTESTINE 0.189 73 Cytotoxic Puromycin CORL311 C LUNG 0.095 75 Cytotoxic CORL88 C LUNG 4.200 34 Insensitive Yes COV318 C OVARY >10 40 Insensitive CT26 C + 0.8 ug/mL INTESTINE >10 −47 Insensitive Puromycin DMS114 C LUNG 0.014 65 Cytostatic DMS273 G LUNG 0.019 80 Cytotoxic Yes DMS53 C LUNG 0.118 66 Cytostatic DMS79 C + 0.8 ug/mL LUNG 0.354 50 Cytostatic Yes Puromycin DU145 F PROSTATE 0.036 74 Cytotoxic Yes Yes EBC1 C + 1 ug/mL LUNG 0.047 83 Cytotoxic Puromycin EGL1 H 0.041 95 Cytotoxic EVSAT G + 2 ug/mL BREAST 0.040 79 Cytotoxic Yes Puromycin GL261 C BRAIN 0.038 85 Cytotoxic HCC1143 C BREAST >10 37 Insensitive Yes HCC1187 I BREAST 0.027 73 Cytotoxic Yes HCC1569 C BREAST 0.067 45 Cytostatic Yes HCC1806 C BREAST 0.014 99 Cytotoxic Yes HCC2218 C BREAST 0.560 41 Cytostatic Yes HCC4006 C LUNG 0.028 57 Cytostatic HCC44 C LUNG 0.131 48 Cytostatic HCC70 I BREAST 0.038 89 Cytotoxic Yes HCC827 C LUNG 0.055 69 Cytostatic HCT116 J INTESTINE 0.041 88 Cytotoxic Yes HCT8 C INTESTINE 0.981 3 Cytostatic HEC108 F ENDOMETRIUM 0.031 90 Cytotoxic Yes Yes HEC1A J ENDOMETRIUM 0.162 56 Cytostatic Yes Yes HEP3B217 F LIVER 0.033 66 Cytostatic Yes HEPG2 F LIVER 0.028 78 Cytotoxic HEYA8 C OVARY 0.112 89 Cytotoxic Yes Yes Yes HGC27 F STOMACH 0.068 78 Cytotoxic HL60 C BLOOD 0.045 87 Cytotoxic HLE B LIVER 0.030 77 Cytotoxic Yes Yes HLF B LIVER 0.017 100 Cytotoxic Yes Yes HOS C BONE 0.090 72 Cytotoxic Yes HS294T K SKIN 0.020 84 Cytotoxic HS766T L PANCREAS 0.062 72 Cytotoxic Yes HT C BLOOD 0.131 64 Cytostatic HT1197 E URINARY 0.281 55 Cytostatic Yes Yes HUH1 M LIVER 0.128 72 Cytotoxic Yes HUH28 A BILIARY 2.896 32 Insensitive Yes Yes HUH7 N LIVER 0.175 64 Cytostatic IGROV1 C OVARY 0.072 70 Cytotoxic Yes Yes IMR32 O CNS 0.002 100 Cytotoxic Yes JHH4 B LIVER 0.166 65 Cytostatic JHH7 C LIVER 0.027 88 Cytotoxic JURKAT P BLOOD 0.061 98 Cytotoxic Yes Yes K562 C BLOOD >10 −191 Insensitive Karpas1106 C BLOOD 0.026 98 Cytotoxic KARPAS299 C BLOOD 0.069 78 Cytotoxic KE97 C BLOOD 0.158 58 Cytostatic KELLY C CNS 0.058 80 Cytotoxic KLE Q ENDOMETRIUM 0.028 65 Cytostatic Yes Yes KP4 L PANCREAS 0.036 65 Cytostatic KPL1 G + 2 ug/mL BREAST 0.668 43 Cytostatic Puromycin KURAMOCHI C OVARY 0.052 88 Cytotoxic KYSE150 R OESOPHAGUS 0.042 64 Cytostatic KYSE180 C OESOPHAGUS 0.103 68 Cytostatic KYSE270 R OESOPHAGUS >10 −180 Insensitive Yes KYSE30 S OESOPHAGUS 0.076 76 Cytotoxic KYSE520 C OESOPHAGUS >10 50 Insensitive KYSE70 C OESOPHAGUS 0.126 70 Cytotoxic Yes LI7 M LIVER 0.132 76 Cytotoxic LN18 T CNS 0.015 91 Cytotoxic Yes LN229 T CNS 0.036 63 Cytostatic LNCAP P PROSTATE 0.059 74 Cytotoxic Yes Yes LS411N C INTESTINE 1.000 45 Insensitive Yes Yes M14 L SKIN 0.032 85 Cytotoxic Yes MCF7 F BREAST 0.155 58 Cytostatic MDAMB157 P BREAST 0.866 39 Cytostatic MDAMB231 U BREAST 2.816 23 Insensitive MDAMB453 U BREAST 0.039 56 Cytostatic MDAMB468 B BREAST 0.008 100 Cytotoxic Yes Yes MDAPCA2B U PROSTATE 6.273 17 Insensitive Yes MDST8 B INTESTINE 0.049 88 Cytotoxic MHCC97H V LIVER 0.243 59 Cytostatic MHCC97L V LIVER 0.526 45 Cytostatic MKN1 C STOMACH 0.023 80 Cytotoxic MKN45 C STOMACH 0.056 79 Cytotoxic Yes MKN7 C STOMACH >10 39 Insensitive Yes MKN74 C STOMACH 0.073 71 Cytotoxic Yes MOLT4 C BLOOD 0.040 99 Cytotoxic Yes Yes MX1 C BREAST 0.045 72 Cytotoxic Yes NCIH1048 W LUNG 0.004 95 Cytotoxic Yes Yes NCIH1092 C LUNG 0.683 42 Cytostatic NCIH1155 B LUNG 0.043 51 Cytostatic Yes NCIH1299 A LUNG 0.195 44 Cytostatic NCIH1436 C LUNG 0.195 56 Cytostatic Yes NCIH146 C + 0.8 ug/mL LUNG 0.030 77 Cytotoxic Yes Puromycin NCIH1666 C LUNG 0.161 59 Cytostatic NCIH1703 C LUNG 0.040 92 Cytotoxic NCIH1734 C LUNG 0.024 76 Cytotoxic Yes NCIH1975 C LUNG 0.021 90 Cytotoxic Yes NCIH2030 X LUNG 5.374 9 Insensitive NCIH2081 W LUNG 0.442 44 Cytostatic Yes Yes NCIH209 C + 0.8 ug/mL LUNG 0.040 83 Cytotoxic Puromycin NCIH2122 C LUNG 0.078 85 Cytotoxic NCIH2196 C LUNG 0.123 63 Cytostatic Yes NCIH2228 C LUNG 0.276 57 Cytostatic Yes NCIH226 C LUNG 1.197 43 Insensitive NCIH2347 C + 0.8 ug/mL LUNG 0.661 45 Cytostatic Puromycin NCIH358 C LUNG 0.042 93 Cytotoxic NCIH441 C LUNG 0.014 84 Cytotoxic NCIH446 C LUNG 0.013 95 Cytotoxic Yes Yes NCIH460 C LUNG 0.047 97 Cytotoxic Yes NCIH520 C LUNG 0.082 77 Cytotoxic NCIH522 C LUNG 0.107 50 Cytostatic NCIH524 C LUNG 0.037 92 Cytotoxic Yes NCIH526 C LUNG 0.018 94 Cytotoxic NCIH596 C LUNG 0.922 46 Cytostatic Yes NCIH69 C LUNG 0.173 68 Cytostatic Yes NCIH727 C LUNG 0.117 56 Cytostatic NCIH82 C LUNG 0.699 22 Cytostatic Yes NIHOVCAR3 Y OVARY 0.040 96 Cytotoxic NUGC3 C STOMACH 0.030 81 Cytotoxic Yes Yes Yes NUGC4 C STOMACH 0.019 83 Cytotoxic OAW42 Z OVARY 0.136 88 Cytotoxic Yes OCUM1 N STOMACH 0.027 82 Cytotoxic Yes OV90 C OVARY 0.034 61 Cytostatic OVCAR5 Y OVARY 0.086 74 Cytotoxic OVCAR8 C OVARY 0.065 90 Cytotoxic Yes OZ AA LIVER 0.050 77 Cytotoxic PANC1 L PANCREAS 0.071 47 Cytostatic PATU8988T C PANCREAS 0.201 55 Cytostatic PLCPRF5 BB LIVER >10 41 Insensitive Raw264.7 C 0.355 62 Cytostatic RKO B INTESTINE 0.118 61 Cytostatic Yes RT112 P URINARY 0.032 87 Cytotoxic SAOS2 CC BONE 0.028 66 Cytostatic Yes SH10TC C STOMACH 0.147 58 Cytostatic Yes SHSY5Y DD CNS 0.059 95 Cytotoxic SiHa F ENDOMETRIUM 0.105 58 Cytostatic SJRH30 C SOFT TISSUE 0.039 62 Cytostatic SKHEP1 BB LIVER 0.118 71 Cytotoxic SKMEL28 B SKIN 0.098 61 Cytostatic SKMES1 F LUNG 0.028 80 Cytotoxic Yes SKOV3 J OVARY >10 27 Insensitive Yes SKUT1 E SOFT TISSUE 0.041 89 Cytotoxic Yes Yes SNU1 C STOMACH 0.105 68 Cytostatic Yes Yes SNU1079 EE BILIARY 0.038 89 Cytotoxic Yes SNU1196 EE BILIARY 0.043 68 Cytostatic SNU16 C STOMACH 0.017 84 Cytotoxic Yes SNU245 EE BILIARY 1.089 −5 Insensitive SNU308 EE BILIARY 0.184 61 Cytostatic SNU387 X LIVER >10 12 Insensitive SNU398 M LIVER 0.021 85 Cytotoxic SNU423 M LIVER >10 40 Insensitive Yes SNU449 C LIVER 1.521 8 Insensitive Yes SNU475 M LIVER 3.917 28 Insensitive SNU478 EE BILIARY 0.032 92 Cytotoxic Yes SNU5 FF STOMACH 0.039 79 Cytotoxic Yes SNU739 C LIVER >10 47 Insensitive SNU869 EE BILIARY 0.052 60 Cytostatic SW1271 U LUNG 0.024 67 Cytostatic SW48 U INTESTINE 0.005 89 Cytotoxic Yes Yes SW480 U INTESTINE 0.036 90 Cytotoxic Yes Yes SW626 U 1.105 39 Insensitive SW780 U URINARY 0.074 68 Cytostatic SW837 U INTESTINE 0.068 55 Cytostatic SW900 U LUNG 3.806 13 Insensitive T47D GG BREAST 0.045 68 Cytostatic Yes T84 HH INTESTINE 0.308 61 Cytostatic Yes T98G O CNS 1.371 44 Insensitive TCCSUP E URINARY 0.040 61 Cytostatic Yes TFK1 II BILIARY 0.040 87 Cytotoxic TGW O BRAIN 0.070 63 Cytostatic THP1 C BLOOD 0.042 81 Cytotoxic TOV112D JJ OVARY 0.025 81 Cytotoxic TOV21G C OVARY 0.061 73 Cytotoxic Yes Yes TYKNU O OVARY 0.072 83 Cytotoxic Yes U118MG B CNS 1.170 42 Insensitive U87MG O CNS 7.356 −5 Insensitive UACC812 U BREAST 0.076 58 Cytostatic Yes UACC893 U BREAST 4.150 −51 Insensitive Yes UMUC3 E URINARY 0.161 70 Cytotoxic ZR751 C BREAST 0.043 69 Cytostatic Media Information: A. RPMI 1640 (Gibco 11835, Gibco 22400-089, or Hyclone Cat # SH30027) + 10% FBS (Gibco cat#10082) B. DMEM with L-Glutamine (Thermo cat#SH30022) + NaPyr + NEAA + HEPES + 10% FBS (Gibco cat#10082) C. RPMI 1640 with HEPES & L-Glutamine (Gibco 22400) + 1 mM Na Pyruvate + 10% FBS(Gibco cat#10082) D. F-12K Medium (Cat#30-2004) + 10% FBS (Gibco cat#10082) E. EMEM (CellGro cat#17-305-CV) + L-Glutamine + Na Pyruvate + Na Bicarbonate + 10% FBS (Gibco cat#10082) F. EMEM (CellGro cat#17-305-CV) + L-Glutamine + Na Pyruvate + Na Bicarbonate + NEAA+ 10% FBS (Gibco cat#10082) G. DMEM (Gibco 11995) + 1 mM Na Pyruvate + 10% FBS(Gibco cat#10082) H. DMEM High Glucose (Hyclone Cat # SH30022) + 10% HI FBS (Gibco Cat # 10082) + 1X NEAA (Hyclone SH30328) I. ATCC modified RPMI 1640 (Gibco A1049101) + 1 mM Na Pyruvate + 10% FBS(Gibco cat#10082) J. McCoy's 5A + 10% FBS (Gibco cat#10082) K. DMEM (Gibco 11965) + 10% FBS L. MEM Eagle with Earle's Salts (Gibco 11095-080) + 1% NEAA + 1% NaPyr + 10% FBS (Gibco cat#10082) M. RPMI-1640 with L-glutamine and HEPES + 10% heat inactivated FBS N. DMEM with L-Glutamine (Thermo cat#SH30022) + Na Pyruvate + 10% FBS (Gibco cat#10082) O. MEM (Gibco 11095) + Na Pyruvate + NEAA + 10% FBS (Gibco cat#10082) P. RPMI 1640 with HEPES & L-Glutamine (Thermo SH30255.01 or Gibco 11835) + 1 mM Sodium Pyruvate + 10% FBS(Gibco cat#10082) Q. DMEM:F12 w/2.5 mM L-glutamine, 15 mM HEPES + 0.5 mM NaPyruv + 10% FBS R. 49% RPMI 1640 + 49% Ham's F12 + 2% h.i. FBS S. 45% RPMI 1640 + 45% Ham's F12 + 10% h.i. FBS T. DMEM (Gibco 11965) + 1 mM Na Pyruvate + 5% FBS (Gibco cat#10082) U. Leibovitz's L15 (Gibco cat#11415-064) + 10% FBS (Gibco cat#10082), No CO₂ V. DMEM with high Glu & L-gln + 10% heat inactivated FBS + NaPyr + NEAA + HEPES W. DMEM:F12 (1:1) + ITS + 10 nM Hydrocortisone + 10 nM beta-Estradiol + 4.5 mM L-glut + 5% FBS (Gibco cat#10082) X. RPMI-1640 with L-glutamine and HEPES + 10% FBS Y. RPMI 1640 with HEPES & L-Glutamine (Gibco 22400) + 1 mM Na Pyruvate + NEAA + 20% FBS(Gibco cat#10082) Z. DMEM + 2 mM Glutamine + 1 mM Sodium Pyruvate (NaP) + 20 IU/l Bovine Insulin + 10% FBS(Gibco cat#10082) AA. Williams' E media (Gibco Cat # 12551) + 10% FBS BB. MEM + 10% FBS + NaPyr + NEAA + HEPES + 1.5 g/L NaHCO₃ CC. McCoy's 5A (Gibco 16600) + 15% FBS (Gibco cat#10082) DD. 1:1 MEM (11095):F12 (CellGro 10-080-CV) + 10% FBS (Gibco cat#10082) EE. RPMI-1640 with glutamine and HEPES (Hyclone Cat # SH30255) + 10% FBS (Gibco Cat # 16000) + 1X NaPyr FF. Iscove's modified Dulbecco's medium w/L-glutamine, 25 mM HEPES [GIBCO 12440-053] + 20% FBS GG. RPMI 1640 with HEPES & L-Glutamine (phenol-red-free) + 1 mM Na Pyruvate + 10% FBS(Gibco cat#10082) HH. 1:1 Hams F12:DMEM + L-Glutamine + 5% FBS (Gibco cat#10082) II. RPMI-1640 (Hyclone Cat # SH30027) + 10% Heat inactivted FBS (Gibco Cat # 10082) JJ. 1:1 mixture of MCDB 105 medium containing a final concentration of 1.5 g/L sodium bicarbonate and Medium 199 containing a final concentration of 2.2 g/L sodium bicarbonate + 15% FBS

TABLE 5 Distribution (%) of anti-proliferation effects of Example 1 across cancer cell lines carrying LOF mutations. Cytotoxic Cytostatic Insensitive (IC₅₀ < 1 μM, (IC₅₀ < 1 μM, (IC₅₀ ≥ 1 μM, % Inh. ≥70) % Inh. <70) % Inh. <70) ARID1A mutants 64%, n = 25 23%, n = 9 13%, n = 5 KMT2D mutants 76%, n = 19 12%, n = 3 12%, n = 3 KMT2C mutants 70%, n = 7 20%, n = 2 10%, n = 1 RB1 mutants 54%, n = 22 37%, n = 15 10%, n = 4 Others 40%, n = 41 44%, n = 45 17%, n = 17 

We claim:
 1. A compound of formula (I):

or a pharmaceutically acceptable salt or enantiomer thereof.
 2. The compound according to claim 1, or a pharmaceutically acceptable salt or enantiomer thereof, wherein the compound is the (S)-enantiomer of formula (II):


3. The compound according to claim 2, or a pharmaceutically acceptable salt thereof, wherein the pharmaceutically acceptable salt is the besylate salt.
 4. The compound according to claim 2, or a pharmaceutically acceptable salt thereof, wherein the pharmaceutically acceptable salt is the hemi-edisylate monohydrate salt.
 5. The compound according to claim 2, wherein the compound is the (S)-enantiomer of formula (II):


6. The compound according to claim 1, or a pharmaceutically acceptable salt or enantiomer thereof, wherein the compound is the (R)-enantiomer of formula (III):


7. The compound according to claim 6, or a pharmaceutically acceptable salt thereof, wherein the pharmaceutically acceptable salt is the besylate salt.
 8. The compound according to claim 6, or a pharmaceutically acceptable salt thereof, wherein the pharmaceutically acceptable salt is the hemi-edisylate monohydrate salt.
 9. The compound according to claim 6, wherein the compound is the (R)-enantiomer of formula (III):


10. A pharmaceutical composition comprising one or more pharmaceutically acceptable carriers, diluents or excipients in combination with a compound of formula (I):

or a pharmaceutically acceptable salt or enantiomer thereof.
 11. The pharmaceutical composition according to claim 10, wherein the compound is the (S)-enantiomer of formula (II):

or a pharmaceutically acceptable salt thereof.
 12. The pharmaceutical composition according to claim 11, wherein: (a) the pharmaceutically acceptable salt is the besylate salt; or (b) the pharmaceutically acceptable salt is the hemi-edisylate monohydrate salt.
 13. The pharmaceutical composition according to claim 10, wherein the compound is the (R)-enantiomer of formula (III):

or a pharmaceutically acceptable salt thereof.
 14. The pharmaceutical composition according to claim 13, wherein: (a) the pharmaceutically acceptable salt is the besylate salt; or (b) the pharmaceutically acceptable salt is the hemi-edisylate monohydrate salt. 